This is why I say the Developer has the final choice,
Game works would die if developers don't use it.
As Silent Guy stated its been 6 years or 4 gens of hardware and AMD still hasn't really fixed its tessellation issues. This is pretty much the only place game works has hurt AMD hardware.
Now lets also talk about older hardware, just turn the features off, Gameworks is supposed to push the graphics up a notch not allow the same visuals with newer end graphics cards with older cards or even lower end cards of the latest gen.
There is no way anyone should expect nV to optimize code for another IHV, as long as it doesn't purposefully down grade performance on another IHV. Its their property and developers have the choice of using it or not.
Now Gameworks is comprised of many different products all of which can integrate with each other, through physics and graphics. This is what developers want, not a piece here and there that Tress Fx is providing.
All that work AMD did with Open Cl and physics, if they continued down that path, tress fx would have also become like gameworks as a whole, but short sightedness, lack of funds or what ever stopped that. ATi was the one with the 1800 series which started with physics on a GPU
. They can't keep complaining about things that they too would have done if they had the funds to do them the way that it was envisioned at the start of a project.
How many of us thought of how powerful physics on a gpu would be and how it would effect graphics? I did, I'm sure many of us all did too.