No way to add comment field to any entity

Problem/Motivation

Core provides only one comment type that bound to nodes.
So when user trying to add a comment field to any other entity type (e.g. user, term) the list of comment types for field storage is empty. User can save the field storage settings without any warnings or exceptions.
But on entity page (user/1) you get

LogicException: A stray drupal_render() invocation with $is_root_call = TRUE is causing bubbling of attached assets to break. in Drupal\Core\Render\Renderer->render() (line 344 of /home/andypost/www/core8/core/lib/Drupal/Core/Render/Renderer.php).

Drupal\Core\Render\Renderer->render(Array, 1)
Drupal\Core\Render\BareHtmlPageRenderer->renderBarePage(Array, 'Error', 'maintenance_page')
Drupal\Core\EventSubscriber\DefaultExceptionSubscriber->onHtml(Object)
Drupal\Core\EventSubscriber\DefaultExceptionSubscriber->onException(Object, 'kernel.exception', Object)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('kernel.exception', Object)
Symfony\Component\HttpKernel\HttpKernel->handleException(Object, Object, 1)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1)
Drupal\Core\StackMiddleware\PageCache->handle(Object, 1, 1)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1)
Stack\StackedHttpKernel->handle(Object, 1, 1)
Drupal\Core\DrupalKernel->handle(Object)

Proposed resolution

Add validation to field settings with a message "Add new comment type at *URL*"
Add check to comment formatter to prevent this exception

Remaining tasks

User interface changes

API changes

Beta phase evaluation