Remember how much people whined going from Win98se or Win2k to Win XP?
It's like 2002 all over again.
Difference is, Win XP is quite useful for most daily tasks. Even being 12 years old.
Admittedly, it didn't become fully that way until SP2, but after that, it was Pretty Decent. Folks have been using it for a decade or longer. Prior Windows OS's kinda sucked but sorta kinda did the job. NT was the first Microsoft OS that didn't lock up or crash on a regular basis, and had at least heard of the concept of "security". Lotta folks used NT for a very very long time because it worked well enough. I wasn't impressed by Windows 2000, but understand that someone might be if they hadn't used NT. I haven't seen any functionality in Vista, 7, 8 or 8.1 that most users really need or want. IMHO, Win 7 is a slightly more stable than XP. Most of my XP boxes I had to reboot at least once a week. Most of my Win7 boxes run for a month or two before needing a reboot.
Microsoft would have less upgrade aversion if they stopped HUGELY fapping about with vastly different interfaces that only a handful of people significantly like. Make a handful of menu options/themes for the eyecandy folks, then put your actual time into security, speed, stability, and value-added crap (like Paint, Snipping Tool, etc). Stop hugely fapping about with the core of the OS unless it's fixing something that is broken or it'd be a huge breakthrough in the speed of the user experience.