Indeed, Richard Stallman is self-described "not an Anarchist".
So? Anarchism has lots of neat ideas and is right about a lot of philosophical things. It's a daunting challenge to convince anyone that it could practically work. On a large scale, it remains only theoretical discussion divorced from reality.
The Hobbesian model of freedom sanctions sovereign violence solely for the purpose of keeping the peace. There is no higher level sanction based on morality. Proprietary software licensing and copyleft licensing are not ajudged against some platonic ideal but only upon their keeping or destroying the peace. There's no deductive proof of inherent goodness, only moment by moment induction. TANSTAAFL.
TANSTAAFL is only true in the broadest sense about opportunity cost, as in I can only live once. Any stronger interpretation doesn't hold true.
Anyway, philosophy philosophy philosophy. It is interesting, may or may not be valid, does inform real life… but it's not the same as discussing the actual details of practical life. GPL lives in real-world social context, less abstract than all this other stuff.
"Richard is against abolishing copyrights because, to his view, without copyright, enforcing copyleft would be impossible."
http://rudd-o.com/monopolies-of-the-mind/thoughts-after-my-d...