This is what happened in 2011.
AMD: DirectX Holding Back Graphics Performance On PC
http://www.gamasutra.com/view/news/123987/AMD_DirectX_Holding_Back_Graphics_Performance_On_PC.php
And yeah... the flexibility that any API like DirectX give to you, where you can make a code to run in almost every PC configuration in the world have a price to be paid... the price is the overhead created by these APIs... if you make a API that access directly the hardware (a fixed hardware and not all the hardware available in the maket) it will performance far better than DirectX but it will be locked to only unique hardware.
That will never change... Windows/Linux/Mac and DirectX/OpenGL/etc hold the graphcis performance on PCs.
Every developer agree with AMD.
Some quotes from AMD...
"It's funny, we often have at least ten times as much horsepower as an Xbox 360 or a PS3 in a high-end graphics card, yet it's very clear that the games don't look ten times as good," he said. "To a significant extent, that's because, one way or another, for good reasons and bad -- mostly good -- DirectX is getting in the way."
"Wrapping it up in a software layer gives you safety and security," Huddy said, "but it unfortunately tends to rob you of quite a lot of the performance, and most importantly it robs you of the opportunity to innovate."
"If we drop the API, then people really can render everything they can imagine, not what they can see -- and we'll probably see more visual innovation in that kind of situation," he said.
