"Configurism" is indeed a mental disorder very hard to live with. In my case it means using the best tool for the job in the most efficient & comfortable way possible.
Nothing ever conformed to this need "out of the box". For instance, I have yet to see a DE that comes with a dark theme as default.
Another take on this problem is functionality. "Jack of all trades, master of none" comes to mind. If you want plug and play gaming, get a console. If you want a PC for gaming, get your hands dirty and set it up that way. The defaults you want aren't the same as those of an accountant's office PC let alone those of a physicist who wants to perform calculations on his machine.
As to all those that didn't read the original blogpost, go and read it. Game performance isn't the point. The point is that kwin is (one of) the last WMs that support multiple rendering paths, and does so in a maintable way (code-wise).
But there is a huge difference (in my eyes) between fiddling with things that I want to change myself - because I would like the change - ... and not because I have to do the change in order for something TO WORK.
If the default theme is not to my preference, then I will change it. But the default theme will still WORK. See?
Changing things that already work, is not a problem. I quite like doing that.
But, with the fact that I'm using Linux, I quite often have to google for hours until I find out how to make something work at all. (I still haven't found out how to make Ibus Chinese Pinyin input work properly in Kubuntu).
I recently installed Linux Mint 14 Cinnamon. And everything worked out of the Box. EVERYTHING! I was very, very happy. But of course, I changed quite a lot of settings to make it the way I wanted it. But it still WORKED! And that is my point in regards to the post on Phoronix that this whole thread is about:
If KDE works better, then great, but I will probably never notice the difference unless it does it out of the box. If I have to switch off compositing manually, then what if I didn't know about that? I would never find out. Even after getting told, I probably wouldn't bother about it unless it gave me a substantial boost in gaming performance. But if the boost is so substantial, then it means there is something wrong with how the game is handled by the OS, because it would leave everybody who doesn't know about this at a huge disadvantage.
As someone here in this thread said: Turning on or off the Aero-theme in Windows doesn't make much of a difference. And that is how it should be, also for us Linux users.
If compositing have to be turned off for fullscreen games to work properly, then I think that should happen automagically :)
Linux is NOT Windows, don't assume both work similarly, because they don't.
If somebody wants to make a Kubuntu fork, tailored SPECIFICALLY for games, he's free to do so.
Really, that's how Linux works, we should have tools, but it's up to the the people to use them.