Well that's the problem... By targeting "vc" with API calls, you remove all possibilities of upgrading the API without breaking something.
When you write something that calls "/restapi/vc/foo", and the foo call needs some change, it will break that code when you change the version vc tartgets.
If, however, you define that from now on "vc" = "v1" and always allow older API versions, my code cannot break even if the new API versions don't have the "foo" call.
In that situation, once I have working enterprise glue code, I never need to change it to use new versions of the API, since it's working as I want and the old API calls remain available.. If I want to use a new API version, I can use the new versions only for the calls I'm changing.
So my point is that providing "vc" is a misfeature.