I think that more and more software is becoming a means to sell your hardware. I would assume that Nvidia wants to utilize as much of the community as possible

I think that more and more software is becoming a means to sell your hardware. I would assume that Nvidia wants to utilize as much of the community as possible to push the next wave of Linux based mobile devices. They aren't really making money off the software anyway, so I doubt it would hurt them to open-source that and it can help them to push their products on more linux based devices.