I see now. It's the crowd of people obsessed with UI tinkering.
Basically all this is not just for decluttering the window but mostly for usability. Just because people are used with the minimize / maximize / close buttons doesn't mean they were a great way to control a window, but that's how people got used to it.
Really? There are reasons things became standard, and they might want to look into them before changing things too dramatically. KDE developers got their asses handed to them for doing this kind of thing and ended up re-implementing old features because real-world user experience found so many of these changes not only distracting due to their scale of the change but detrimental to productivity even when they'd gotten accustomed to it.
I admit I don't use the max button, mostly because I rarely maximize a window anymore. The bountiful screen real estate available with modern displays allows one to have several usable windows on the desktop at one time, and maximizing them defeats the purpose. In fact I get annoyed with apps that effectively disable the custom size of windows I set. I have groups of applications I use a lot at the same time, and I have their window sizes set so that they can all be open at once on the same screen. Occasionally an app will come along that reverts to its default size, which is invariable too big. The max button could go away, and I wouldn't notice.
Whether I use the min button depends on where my pointer is at the time I decide to minimize.
I would have trouble dealing with a close button that wasn't either on the far left or far right that could simply be clicked. A gesture for this is dumb and seems to come from the mind of those who kept trying to insist that clicking on the file menu and the close option there was somehow "better" than using the X. I even saw some apps back in Win 3.1 that intentionally added a little shutdown procedure to their application to force this or risk losing data. I never understood it. Seemed like a massive degree of hubris on the part of those who insisted they knew what was best about a UI experience.
And I think a lot of developers are this way. Most of them work for Microsoft, but this seems to be a pattern of behavior that's leaking into the OpenSource world as well. The things I see some developers doing with touch screens, just because they can not because it is efficient or user friendly, are truly annoying. I can hardly wait for the first app to come along that *requires* using all ten fingers on a touch screen just to move a window where you want it to go ... and listen to some designer dweeb tell me how this is better than click-drag.