Don't get me wrong - I am ALL ABOUT the new APis from a technical standpoint. But I'm not living in AAA world these days and practical reality is that writing a render pipeline for a market that maxes out at 22% is just a bit rough. Now it's very helpful that Win10 is free and everyone wants to get the hell out of Win8. But the real key point is that it's very difficult, outside of a few select high budget things, to really design around the new APIs. Oxide's been talking about this, where you really start leveraging the added capabilities in a way that is more extensive than simply writing multiple render pipelines, and those changes feed all the way up to your game design.
FWIW I am shipping a Metal pipeline game in a few weeks - which is more about the structure of Apple's platform than anything - and that's not designed around the new rendering API either. I still have to maintain GL ES paths for a wide swath of old devices and that means the rendering changes are low hanging fruit with a lot of old assumptions and limitations still preserved.