I've never worked on drivers at NVidia, so on the one hand I don't know the answer, but I can speculate with an educated guess. Porting, testing and providing

I've never worked on drivers at NVidia, so on the one hand I don't know the answer, but I can speculate with an educated guess. Porting, testing and providing ongoing support for an OS is very costly. If there's not enough customer demand for it, it won't be done because it doesn't make business sense.