I'm convinced 80% on the internet don't know how to right click a hyperlink to open it in a new browser window. That they are constantly using the forward and backward buttons
they can't figure out how to use anti-virus software, they can't figure out how to use ad-aware programs, install a wireless network, etc. I look at it from the other direction: why have we as an industry failed to make interfaces intuitive and consistent enough for the average person to do these things?
Again I'm parroting an earlier post of mine, but evidently it needs repeating: why should there be this expectation of the end user?
Windows (wintel machines) has one expectation and Apple another. Is this such a bad thing?
MacOS X is very impressive in this sense. It has an intuitive and consistent interface,
Windows is supposed to be this too. My guess is the Apple GUI does it better
but you have the CLI for people who need more power so you don't give that up either.
Windows is a horror from a user-interface perspective. Mac is much better, except for the Dock, which is a gee-whiz feature they developed to try to lure Windows users used to the task bar.