No, what I mean with XFCE and Englightenment is that they admit being alpha.

Yeah, well the reality is that NVIDIA drivers are the drivers one wants to use on NVIDIA hardware (which many of us have.

And somehow they work fine on X11.

It's always nice to blame the driver vendor, but what has the Linux community the kernel team, the graphics team done to promote Linux and make it simple to write correct performant drivers for the platform? How many graphics memory allocations are there? How many buffer sharing APIs, are the kernel driver interfaces stable?

When other driver vendors have been able to work with the kernel team quite successfully, I think it starts to become fair to blame the other vendor.