Why would that be a legal right?

Why should we hand over even MORE power to the owner class?

In a fantasy world this could be possible yes.

Copyright (or any other such restriction on free use of information) creates power for owners by the simple fact that it turns information into something that can be owned.

Make it a right, then companies/universities will think twice before using said APIs. Instead of this grey area where we will never know.

We don't hand over more power to the owner class by making fewer things ownable.