Windows 7 made everyone forgive and forget the monstrosity that was Vista... XP made everyone forgive and forget the monstrosity that was Windows ME... Vista and ME are about 100x worse than windows 8 ime. at least Windows 8 can run with some stability. and the start screen (the biggest problem) can be easily and safely ignored with 8.1... (I haven't even seen it in over 2 months.)
windows 8.1 runs smoothly and quickly on my 3 year old i5, and has been rock solid. I've never had a vista install last, and don't get me started on ME. I installed it, and less than a month I was getting nothing but daily blue screens. I've never once seen a blue screen in 8.1. (I have in 7)
Also, I've been around for quite a while. I remember when XP came out. the outcry against the new start menu was just as bad as the outcry about the start screen is currently. People called it a monstrosity, and how could they remove the my computer icon from the desktop. how dare they... granted they had the classic start menu still there, but the default was "unacceptable".
Heck Windows 95 came out to much arguing and angst as well. "Windows 95 won't run on my 386, what a piece of junk! who needs this fancy GUI anyway, why can't I just boot it to DOS and run the gui when I need to!" "I have to click 'start' to shut my computer down? What kind of nonsense is this?" "windows 95 will flop!"
Coming back more recently... Windows 7... the removal of the quick launch toolbar... i can't begin to tell you how many people were pissed off about that. (I personally find pinning to the task bar a more acceptable way to handle it than a quick launch tool bar, but try to explain that to some people...
Any change Microsoft makes is called a "horrific mistake"... but people will get used to it. and things continue as they always have. the hold-outs will find work-arounds. but eventually it'll work out.