According to Steve Jobs, the Mac now makes up 20% of total computer sales. I personally know of about a dozen people that have switched from PC to Mac,but none that have gone the other way....
Just because people choose a Mac over a PC, doesn't make it a good choice. The main requirement is more money than sense. Most people know more about cars than computers & they just buy a car they can afford and like the look of.
If you've ever been in pc world when one of their sales people are upselling, you'd realise just how clueless everyone is.