Also, windows is closed source. Its full of NDAs. Opensource and closed source do not exist together easily (unless its call-girl BSD, with result = proprietary).
In order to achieve same level of integration, manufacturers should spend at least same amount of resources, which they don't do.
It would be a lot easier for proprietary to integrate, if Linux were proprietary, but that would mean every Linux developer will have to sign NDA, which is likewise impossible, as Linux chances to survive along and in case being itself proprietary OS.
So, no NDA possible, manufacturers do not target Linux for the same market(I am not speaking about community), they do not dump same amount of cash on development and ignore your opinion.
Your behavior is like swearing on David for being no match to Goliaph, while silently enoying buttseks with the later.
The open driver stack is showing 40-70% performance of the closed driver with OpenGL 3, and that only within several years of development.
So, if you don't want to support the development (instead of crying like small babies), do whats acceptable for you. Along with consequences.
And regarding this:
If you are a developer - you are free to make your own.
Lennard clearly stated that he has no intention to pull the train of legacy/compatible systems along.
This is his way to concentrate development time to make Linux much more competitive to ... windows (yes) and apple. Was that your problem? Then who is hypocrite?
When the technology is ripe enough, any system can port the stabilized changes back, because its opensource and nobody looses. Unlike the proprietary trash you seem to enjoy, which only works well on one OS.