I found same problem (bug?) with having no admin/commerce/products/variations page.
So comparing my "vanilla" drupal install with the "commerce kickstart" install I found a view that is missing so I did a views export from the kickstart site and a views import to my site and all was good. I just needed to also enable the commerce display manager module as well which provides the correct link for adding new products (another bug? the add product link on the products page sends me to the add product node page). Now on the product display manager page there is a link to the admin/commerce/products/add page.

This has been a confusing mess...but I think I might like the modular system better than our other options, and eventually these bugs should be worked out.

following is a cut and paste of the views export-import that I used to accomplish the admin/commerce/products/variations page

********************************************************************
$view = new view();
$view->name = 'commerce_backoffice_all_product_variations';
$view->description = '';
$view->tag = 'default';
$view->base_table = 'commerce_product';
$view->human_name = 'Commerce Backoffice: All Product variations';
$view->core = 7;
$view->api_version = '3.0';
$view->disabled = FALSE; /* Edit this to true to make a default view disabled initially */

/* Display: Master */
$handler = $view->new_display('default', 'Master', 'default');
$handler->display->display_options['title'] = 'Product variations';
$handler->display->display_options['css_class'] = 'commerce-backoffice-view';
$handler->display->display_options['use_ajax'] = TRUE;
$handler->display->display_options['use_more_always'] = FALSE;
$handler->display->display_options['access']['type'] = 'perm';
$handler->display->display_options['access']['perm'] = 'administer commerce_product entities';
$handler->display->display_options['cache']['type'] = 'none';
$handler->display->display_options['query']['type'] = 'views_query';
$handler->display->display_options['exposed_form']['type'] = 'basic';
$handler->display->display_options['exposed_form']['options']['autosubmit'] = TRUE;
$handler->display->display_options['pager']['type'] = 'full';
$handler->display->display_options['pager']['options']['items_per_page'] = '50';
$handler->display->display_options['style_plugin'] = 'table_megarows';
$handler->display->display_options['style_options']['columns'] = array(
'views_bulk_operations' => 'views_bulk_operations',
'sku' => 'sku',
'title' => 'title',
'type' => 'type',
'commerce_price' => 'commerce_price',
'status' => 'status',
'operations' => 'operations',
);
$handler->display->display_options['style_options']['default'] = 'sku';
$handler->display->display_options['style_options']['info'] = array(
'views_bulk_operations' => array(
'align' => '',
'separator' => '',
'empty_column' => 0,
),
'sku' => array(
'sortable' => 1,
'default_sort_order' => 'asc',
'align' => '',
'separator' => '',
'empty_column' => 0,
),
'title' => array(
'sortable' => 1,
'default_sort_order' => 'asc',
'align' => '',
'separator' => '',
'empty_column' => 0,
),
'type' => array(
'sortable' => 1,
'default_sort_order' => 'asc',
'align' => '',
'separator' => '',
'empty_column' => 0,
),
'commerce_price' => array(
'sortable' => 1,
'default_sort_order' => 'asc',
'align' => '',
'separator' => '',
'empty_column' => 0,
),
'status' => array(
'sortable' => 1,
'default_sort_order' => 'asc',
'align' => '',
'separator' => '',
'empty_column' => 0,
),
'operations' => array(
'align' => '',
'separator' => '',
'empty_column' => 0,
),
);
$handler->display->display_options['style_options']['empty_table'] = TRUE;
$handler->display->display_options['row_plugin'] = 'fields';
/* Field: Bulk operations: Commerce Product */
$handler->display->display_options['fields']['views_bulk_operations']['id'] = 'views_bulk_operations';
$handler->display->display_options['fields']['views_bulk_operations']['table'] = 'commerce_product';
$handler->display->display_options['fields']['views_bulk_operations']['field'] = 'views_bulk_operations';
$handler->display->display_options['fields']['views_bulk_operations']['label'] = '';
$handler->display->display_options['fields']['views_bulk_operations']['element_label_colon'] = FALSE;
$handler->display->display_options['fields']['views_bulk_operations']['vbo_settings']['display_type'] = '0';
$handler->display->display_options['fields']['views_bulk_operations']['vbo_settings']['enable_select_all_pages'] = 1;
$handler->display->display_options['fields']['views_bulk_operations']['vbo_settings']['force_single'] = 0;
$handler->display->display_options['fields']['views_bulk_operations']['vbo_settings']['entity_load_capacity'] = '10';
$handler->display->display_options['fields']['views_bulk_operations']['vbo_operations'] = array(
'action::views_bulk_operations_delete_item' => array(
'selected' => 1,
'postpone_processing' => 0,
'skip_confirmation' => 0,
'override_label' => 1,
'label' => 'Delete product variation',
),
'action::views_bulk_operations_script_action' => array(
'selected' => 0,
'postpone_processing' => 0,
'skip_confirmation' => 0,
'override_label' => 0,
'label' => '',
),
'action::views_bulk_operations_modify_action' => array(
'selected' => 0,
'postpone_processing' => 0,
'skip_confirmation' => 0,
'override_label' => 0,
'label' => '',
'settings' => array(
'show_all_tokens' => 1,
'display_values' => array(
'_all_' => '_all_',
),
),
),
'action::views_bulk_operations_argument_selector_action' => array(
'selected' => 0,
'skip_confirmation' => 0,
'override_label' => 0,
'label' => '',
'settings' => array(
'url' => '',
),
),
'action::system_send_email_action' => array(
'selected' => 0,
'postpone_processing' => 0,
'skip_confirmation' => 0,
'override_label' => 0,
'label' => '',
),
);
/* Field: Commerce Product: SKU */
$handler->display->display_options['fields']['sku']['id'] = 'sku';
$handler->display->display_options['fields']['sku']['table'] = 'commerce_product';
$handler->display->display_options['fields']['sku']['field'] = 'sku';
$handler->display->display_options['fields']['sku']['link_to_product'] = 0;
/* Field: Commerce Product: Title */
$handler->display->display_options['fields']['title']['id'] = 'title';
$handler->display->display_options['fields']['title']['table'] = 'commerce_product';
$handler->display->display_options['fields']['title']['field'] = 'title';
$handler->display->display_options['fields']['title']['link_to_product'] = 1;
/* Field: Commerce Product: Type */
$handler->display->display_options['fields']['type']['id'] = 'type';
$handler->display->display_options['fields']['type']['table'] = 'commerce_product';
$handler->display->display_options['fields']['type']['field'] = 'type';
$handler->display->display_options['fields']['type']['link_to_product'] = 0;
$handler->display->display_options['fields']['type']['use_raw_value'] = 0;
/* Field: Commerce Product: Price */
$handler->display->display_options['fields']['commerce_price']['id'] = 'commerce_price';
$handler->display->display_options['fields']['commerce_price']['table'] = 'field_data_commerce_price';
$handler->display->display_options['fields']['commerce_price']['field'] = 'commerce_price';
$handler->display->display_options['fields']['commerce_price']['element_type'] = '0';
$handler->display->display_options['fields']['commerce_price']['element_wrapper_type'] = '0';
$handler->display->display_options['fields']['commerce_price']['element_default_classes'] = FALSE;
$handler->display->display_options['fields']['commerce_price']['click_sort_column'] = 'amount';
$handler->display->display_options['fields']['commerce_price']['type'] = 'commerce_price_formatted_amount';
$handler->display->display_options['fields']['commerce_price']['settings'] = array(
'calculation' => '0',
);
$handler->display->display_options['fields']['commerce_price']['field_api_classes'] = TRUE;
/* Field: Commerce Product: Status */
$handler->display->display_options['fields']['status']['id'] = 'status';
$handler->display->display_options['fields']['status']['table'] = 'commerce_product';
$handler->display->display_options['fields']['status']['field'] = 'status';
$handler->display->display_options['fields']['status']['type'] = 'active-disabled';
$handler->display->display_options['fields']['status']['not'] = 0;
/* Field: Commerce Product: Operations links */
$handler->display->display_options['fields']['operations']['id'] = 'operations';
$handler->display->display_options['fields']['operations']['table'] = 'commerce_product';
$handler->display->display_options['fields']['operations']['field'] = 'operations';
$handler->display->display_options['fields']['operations']['label'] = 'Operations';
$handler->display->display_options['fields']['operations']['add_destination'] = 0;
/* Sort criterion: Commerce Product: Created date */
$handler->display->display_options['sorts']['created']['id'] = 'created';
$handler->display->display_options['sorts']['created']['table'] = 'commerce_product';
$handler->display->display_options['sorts']['created']['field'] = 'created';
$handler->display->display_options['sorts']['created']['order'] = 'DESC';
/* Filter criterion: Commerce Product: Type */
$handler->display->display_options['filters']['type']['id'] = 'type';
$handler->display->display_options['filters']['type']['table'] = 'commerce_product';
$handler->display->display_options['filters']['type']['field'] = 'type';
$handler->display->display_options['filters']['type']['exposed'] = TRUE;
$handler->display->display_options['filters']['type']['expose']['operator_id'] = 'type_op';
$handler->display->display_options['filters']['type']['expose']['label'] = 'Filter by';
$handler->display->display_options['filters']['type']['expose']['operator'] = 'type_op';
$handler->display->display_options['filters']['type']['expose']['identifier'] = 'type';
$handler->display->display_options['filters']['type']['expose']['multiple'] = TRUE;
$handler->display->display_options['filters']['type']['expose']['remember_roles'] = array(
2 => '2',
1 => 0,
3 => 0,
);
/* Filter criterion: Commerce Product: Status */
$handler->display->display_options['filters']['status']['id'] = 'status';
$handler->display->display_options['filters']['status']['table'] = 'commerce_product';
$handler->display->display_options['filters']['status']['field'] = 'status';
$handler->display->display_options['filters']['status']['value'] = 'All';
$handler->display->display_options['filters']['status']['exposed'] = TRUE;
$handler->display->display_options['filters']['status']['expose']['operator_id'] = '';
$handler->display->display_options['filters']['status']['expose']['operator'] = 'status_op';
$handler->display->display_options['filters']['status']['expose']['identifier'] = 'status';
$handler->display->display_options['filters']['status']['expose']['remember_roles'] = array(
2 => '2',
1 => 0,
3 => 0,
);
/* Filter criterion: Global: Combine fields filter */
$handler->display->display_options['filters']['combine']['id'] = 'combine';
$handler->display->display_options['filters']['combine']['table'] = 'views';
$handler->display->display_options['filters']['combine']['field'] = 'combine';
$handler->display->display_options['filters']['combine']['operator'] = 'contains';
$handler->display->display_options['filters']['combine']['exposed'] = TRUE;
$handler->display->display_options['filters']['combine']['expose']['operator_id'] = 'combine_op';
$handler->display->display_options['filters']['combine']['expose']['operator'] = 'combine_op';
$handler->display->display_options['filters']['combine']['expose']['identifier'] = 'combine';
$handler->display->display_options['filters']['combine']['expose']['remember_roles'] = array(
2 => '2',
1 => 0,
3 => 0,
);
$handler->display->display_options['filters']['combine']['fields'] = array(
'sku' => 'sku',
'title' => 'title',
);

/* Display: Admin page */
$handler = $view->new_display('page', 'Admin page', 'page');
$handler->display->display_options['path'] = 'admin/commerce/products/variations';
$handler->display->display_options['menu']['type'] = 'tab';
$handler->display->display_options['menu']['title'] = 'All product variations';
$handler->display->display_options['menu']['weight'] = '20';
$handler->display->display_options['menu']['context'] = 0;