It could be a conspiracy, or it could just be that developers implement those features when they get money/help from nVidia and AMD, and don't when they don't. Or maybe AMD's offering is easy to implement and nVidia's isn't. I vaguely recall that nVidia's is tied to the game more tightly than AMD's is, but don't quote me on that.
In the end, I expect we'll eventually converge on a system that both work with, and this'll all just be a blip in history, like every other standard worth supporting.