If you're a gamer...?
Seriously, I think some gamers are living in the cloud. PC gaming is a niche*, and the Mac has been pushing steadfastly into that niche in recent years. With Steam's release on Mac last year that situation took an huge step forward (even if not all the games came with it).
As for the last 15 years; Apple was pretty much on it's knees 15 years ago yet today it dominates many of the markets MS has been targeting for what seems like forever; mobiles, music, tablets, mobile computing. And it's doing it with pricey hardware that should by all means make entry to market more difficult for them.
* I'm a a PC gamer and I recognise that the field we're playing on is changing (Been into GAME recently?). But I also recognise that my niche is being threatened by consoles far more than Macs. Ironically, MS's own console...