The cynic in me suspects this is the attitude of many UI designers.
That said, you can do a quick mental checksum on the idea:
The classic MacOS, for instance, never had a minimize button. It did eventually have a window shade capability and later a windows shade button but I used system 7 for ages without minimize and suffered no ill effects for the experience.
I never use MacOS X's minimize feature since it's redundent with the "hide application" capability of that OS. You can hold down the option key while clicking on a window of another application in the background and it will hide all the windows of the application you're switching from.. for example.. If you hold down option and comand it will hide all applications except the one you're switching too. I find this feature much more usefull in MacOS X. I sometimes click this MacOS X's minimize button by accident and it makes the window harder to find later. Personally, I'd remove the buttons if I could.
I do use the minimize button in gnome and windows 7 however. I'm not sure if I'll miss it if it's gone.
On the topic of maximise,
I use Windows 7 fairly often and have basically stopped maximing windows. The reason is that I have 3 1080p monitors. On these monitors I usually don't want to maximize windows because this almost always results in a window that is too wide. I tend to double click the top or bottom of the window to "maximize" the window's hight automatically. This is the greatest new feature in Windows 7 IMHO. The only downside to this is that when you try and move a window horizontally, there's only a small distance you can move the mouse cursor vertically before the window "unsnaps" from its vertical maximization. I often want to move these windows between monitors and so I'd like the system to keep the windows veritcally maximized while I drag them around.
The classic MacOS didn't have a maximize button either. It did have a button that was supposed to resize the window to the minimum size required in order to show a window's contents. Much of the time this effectively maximized a window. There was a MacOS convention to have a small border area between the edge of the screen and the window when you did this. You could this this edge with an option-command-click to rapidly jump to the Finder and hide all other windows. If I had a choice I would bring this smart-resize button back. Also the option and option-command click features. The smart resize button is still there in MacOS X but often mistaken for a maximize button. Maybe because it's green and has a "+" on it.. or maybe because it's often implemented wrong... or "wrong". This makes me cry into my grey beard.
So life is indeed possible without a minimize or maximize. To me it seems somewhat arbitrairy to remove them though. I mean why? You can add new features to make using windows on multiple, large monitors easier without removing the buttons.. If the new features make the two buttons redundent *then* you can remove the tem.. Anyway, I'm not ready to grab a pitchfork over it.