What if one of the companies had an advantage, such as being the developer of both the original API itself, and the translation layer... as well as the OS itself... and also has direct access to hardware vendors to help provide driver support?? Not to mention that company having VAST amounts money and an incentive to do it.If hobbyists couldn't get their Mantle translation layer to run on other vendors then there's no hope to achieve better results with modern console APIs ...
I'm sure there's more hope in a company like that, than hobbyists who have little control over any of those things.