Judging from what I've seen of their drivers, yeah, their firmware/microcode is probably an embarrassing bug-ridden code base. But it also represents a lot of investment in low-level/low-layer features that they would prefer to hide from competitors (much more sensitive than the higher-layer logic in the driver proper).
While I can understand that sentiment and perspective. Those people are wrong, they are inconveniencing their competitors to a tiny degree and over estimating the value of those features due to the awful implenation.
