Why NVidia(and AMD) won't opensource linux drivers

So much ranting about the topic on the internet, yet nobody has any clue. The crux of the matter is probably in NVidia Quadro (and AMD/ATI FireGL) cards which for most part only differ from the significantly less expensive "gamer" cads in the driver behavior - proper stereo support, antialiased lines, and such.

Those highly overpriced cards do serve a business purpose; them allow to cover development costs and generate extra profits while releasing cheaper cards for the masses. I wish they would come up with some hardware difference, such as 10% faster for 3x the price as common for the CPUs - but with every clueless gamer wanting 'overclockable' cards, it probably wont happen.

Open source drivers, whenever made through reverse engineering or with documentation available, are of no concern to either due to lack of manforce to make those drivers usable. People whom don't work in computer graphics don't quite appreciate the fact that 3D graphics card 'driver' is far more complicated than network card driver or sound driver; I'd say 3D card driver is an entire operating system in itself - with memory management, shader and OpenCL compilers, multitasking (for multiple OpenGL contexts), and such. The graphics card is a computing system of it's own.