This is just ridiculous. The other points may/may not make sense but drop direct-x for vulkan? What? It'd have made more sense to make Direct-X open source than just dump it like it's useless. It's not like windows drivers for GPUs don't support vulkan.
Direct-X has had a history of being the superior graphics API to OGL. Now, VULKAN evens things out a bit but just dumping so much of RnD for nothing doesn't make sense
But to summarize: OpenGL was the standard before D3D was created. D3D has been a step behind OpenGL in features and performance up to about D3Dv7. Then the OpenGL ARB screwed up, with Microsoft among the members (some hypothesize that Microsoft were attempting to sabotage OpenGL).
