The limits in other sectors are almost universally to prevent harm, injury, or otherwise unpleasant outcomes. How is installing OSX on standard hardware injurious to anybody? Apple made a sale, and the user gets what they want. What other similar situations are you thinking of, kryyst?

I don't personally care one way or the other and am quite content with my Ubuntu and Win 7, but it just seems fallacious to me, and like something that very few companies would ever get away with.