Q:

Is it possible to create a report (type) for custom metadata?

Custom metadata (types) looks like a cool feature. I have created dozens of instances of one that I made and now I would like to create a report on them, because a list view is not good enough.
So first I need to create a report type for this, as the type is not available when creating a report, but my custom metadata type is not in the list of objects for which I can make a report type.
When creating or modifying the custom metadata type, it says "The singular and plural labels are used in tabs, page layouts, and reports."
This suggests that it is possible to create a report. But how do I do that?

A:

The reports documentation states that 

Reports give you access to your Salesforce data

While Custom Metadata is not considered as data

You can create your own declarative developer frameworks for internal
  teams, partners, and customers. Rather than building apps from data,
  you can build apps that are defined and driven by their own types of
  metadata. Metadata is the information that describes the configuration
  of each customer’s organization.

Emphasis on metadata is mine in the quote. So basically it is not possible to create report on Custom metadata since reports can be created from data, while Custom metadata is not considered as data, but rather as metadata.
When we read about creation of custom report type, we can find references to two of three types of objects.

If the primary object on a report type is a custom or external object,
  and that object is deleted, the report type and reports created from
  it are deleted.

Emphasis on  custom or external object is mine.
So, reports are not available not only to custom metadata or custom settings but even for big objects despite they are actually data.

