I think Linus was mainly upset about the state of NVIDIA support for
GNU/Linux. I somehow think Linus doesn't care whether that means more support
for the proprietary driver or nouveau.
NVIDIA used to maintain the free nv driver, but apparently it was never very
good. It got abandoned by NVIDIA in favour of their proprietary driver, and
so nouveau forked it.
Some links I found interesting about the nv/nouveau incident:
http://www.abclinuxu.cz/clanky/rozhovory/andy-ritger-nvidia?page=1 (see point
5)
http://www.phoronix.com/scan.php?page=news_item&px=ODQ2MQ
http://nouveau.freedesktop.org/wiki/FAQ#Do_you_get_any_support_from_NVidia.3F
