I agree with your quote: "Windows needs constant user-help to maintain itself."
People will only defrag, scan for viruses, un-install programs (and the list goes on and on and on) WHEN WINDOWS IS PLAYING UP AND/OR RUNNING SLOW.  I know some small businesses who make money out of fixing slow computers running Windows.  I'm sure Linux can be defragmented and I reckon my own Linux drive is fragmented, but the performance is so fast that it's not a problem.  If Ubuntu Linux ever started going slow, I would need to worry about performing the necessary maintenance that Windows users have to constantly battle with, but so far Ubuntu is running as fast as it did on day one - with no constant maintenance.  So yes, "Windows needs constant user-help to maintain itself."