What you quoted is just the person restating the paradox of tolerance. It's totally nonsensical once you get past "one-dimensonal evil" cases (or perhaps cases like software, a category is more narrowly and cleanly delineated).

He's right that freedom requires restriction. The problem with the paradox of tolerance is that it masquerades as a meaningful principle while leaving the actual restrictions unnamed.

P.S. it also is worth noting that, to the extent that the GPL works, it's precisely because it doesn't rely on vague principles. It's specific about what's restricted, when, and how.