You know what would have been an incentive for me (and I guess thousand of other game devs) to support windows phone? Support for OpenGL ES.
Just as side note, Microsoft did port ANGLE to WP.
No, I will continue using OpenGL ES.
Anyway: Apple can afford pushing it's own API due to market share, Microsoft could not.
> Just as side note, Microsoft did port ANGLE to WP.
I know, but it didn't support a feature I needed at the time and also it was quite a hassle. Together with the non-GCC/Clang compiler it was just too much.