[kazinator]

> Who is claiming this is a copyright issue?

Why, Stallman and the FSF. Their license is even called "copyleft".

Software licensing is not separate from copyright. Licensing restrictions are made possible by copyright.

There are fantasy clauses in software agreements which don't have anything to do with copying; they are probably bogus. (Like that you can't look at the code to understand how it works, even though you paid for it, and are doing the looking on the machine which holds the licensed copy.)