A computer is a computer, there aren't any special components needed for a certain OS.
Apple is just greedy, and feels the need to make it seem that way (as most people seem to think that there is something different between them and others, when besides price there isn't), when really every Mac computer is just as good as a PC, but costs 50% more than the same components on a PC.
This is, of course, an explanation that assumes that your whole basis for thinking Linux had its own computers was because Apple and Microsoft do.