Well just so you know I am a video game developer. No I am not selling any video games or worked on any video games that are for sale and have been released for sale.Developers who have to deal with it really care. Choice of technology will determine where their programs could be used. MS could shove their closed APIs on people only because of the market domination. With the situation changing, it will only backfire on them, when people will stop using MS exclusive APIs, because they care about better platforms coverage.
Consoles wise, I think Steam machines will deal a really fatal blow to Xbox. That would spell the end of DirectX potentially, but it will take time. Valve did something really incredible here - practically managed to lay a foundation of dismantling MS monopoly.
I started modding in 1998 when I purchased my first PC when I purchased my first PC video game Unreal. In 2002 when the PC version of The Elder Scrolls III: Morrowind released for sale I was modding it and in 2002 is also when I started learning how to code and script every now and then. Then in 2010 I went to college learning C, C++, Visual Basics, and Java Script for 3 years.
I use Unreal Engine 3, CryEngine 3, now CryEngine every week. Soon hopefully Unreal Engine 4. I also use DirectX 9, DirectX 10, and DirectX 11.
CD Projekt RED also seem to prefer DirectX over OpenGL. They announced they will support Linux on gog.com this year in the Fall but they said Microsoft offers better tools for DirectX. VALVe, AMD, Intel, and Nvidia are working on developing better tools for OpenGL now.
So we will see what CD Projekt RED says about OpenGL in a year from now or 2 years from now.