Apple did a whole "I'm a Mac / I'm a PC" ad campaign a few years ago...
Ah that explains something. Leave it to Apple to make people dumber.
I am sorry a mac IS NOT a PC IMO
Your opinion does not change the facts (there was a WikiPedia article in an earlier post).
Whether something is a PC or not is entirely related to the *hardware*, the Operating System has no relevance. Windows and Mac OS X run on the same hardware, ergo if one runs on PCs then the other does as well.
Of course, Apple tries to prevent or at least discourage you from running OS X on generic Intel-compatible hardware, they wouldn't want people to be able to get a Mac OS X machine for €300 if they can get them to buy their overpriced (imho) stuff instead...