I agree to the above in a painful way. I don't think of myself as a power user but I have at times to clean up the registry for stuff that uninstallers missed because the updated application does not want to install. It's a complete mess of having to dig through a tip to find a broken match box so you can destroy it without setting on fire the whole thing.

Meanwhile OS X or Linux don't suffer from this and working with applications is a lot more "streamlined". As I said, this is just a slightly above average skilled end-user perspective.