But very, very few apps ever get it right, and most people seem to just want minimize and maximize.
Hell, what proportion of them use desktop-variety computers?
I maintain that people think of multi-windowed UI in terms of windows first. Resizing a window to fit the content makes less sense than resizing the content to fit the window. People also seem to get really upset when UI interaction isn't consistent, and the Mac approach means that it varies wildly between apps.