From what I understand, nvidia would probably be amenable to make a completely GPL'ed module, but they *can't*. There's parts of it that are covered by technologies and patents they don't own, and don't have permission to release for free.
They're doing the best they can, and a pretty good job of it. Deliberately cutting them off because they're not perfectly conforming to the One True Way Which You Shall Follow Or Be Assimilated For Resistance Is Futile is a very Microsoft way of doing business.
What was that saying again Nietsche had about fighting monsters?