I think it was David Berry who compared the GPL to a guild rather than a commons.
It is an ironised guild, inclusive rather than exclusive, but it is a good comparison.
I would go further and compare the GPL to a union (a trade union). It represents workers (programmers) and can withdraw their labour (their code) if a dispute arises (if the GPL is broken).
The GPL does not seek any advantage for its members (programmers who use it) other than that they be allowed to continue to work. And to be fair this is all Stallman sought to do. It might be nice if the GPL could “strike” for better conditions or pay, but being able to work is a minimum. And the GPL does keep the direct fruits of programmers labour for them, their code.
In a way it gives the workers the means of production (derivation). But it also destroys the value of their labour. It’s this sort of thing that makes leftist or libertarian analyses of the GPL so difficult. 🙂