It's not quality.
Some people have always liked Mac, so for them, great, do the thing you like. For others it's buying into an image.
It's very much like the Harley Davidson situation. Some slightly geeky supervisor who eats shit all day goes and buys a Harley, he's the one with all black studded leathers and the skull bandana wrapped around his face. He's bad ass because he's on a Harley.
Those same style Apple users are ____________ because they have a Mac.
Fill in the blank with whatever those people think they are, because they sure as hell aren't computer savvy in any way.