And you don't have to be affluent in Windows to fix issues? Get real. There is a reason Best Buy and other places can charge hundreds by the hour to have some 17 year old dropout of high school check it out using their "Geek Squad" service.
Most of the places don't even know what they are doing half of the time. There have been plenty of videos posted online whereby a TV program will go and turn in machines to various places with a simple to fix issues and be told that the motherboard is dead, that there is a virus and it needs to be re-installed (re-installation fees get expensive fast) and other crap.
No, the people that can be tricked into believing that KDE is Windows 7 will not know how to fix Windows when the time comes, and will be more susceptible to downloading random crap that takes over their machines in the first place.