Cater to naive users. I say this as someone who particularly dislikes Apple's way of doing things, but who still recommends OSX to naive users.

Something goes wrong with linux? Better hope there's a congenial neckbeard around, and if it's a hardware problem, good luck to you. In OSX? A larger online presence, and then of course you can always take it into a "genius" bar... and they replace the hardware gratis often enough.