The first half dozen of Conan's points pretty well sum up the case for the prosecution I think, and you can add higher initial cost.
The case for the defence can be found all over this forum if you search for it. It's a subjective thing, and no amount of huffing and puffing from either side will change the opinion of the diehards on the other.
I'll just suggest that Mac users can be perceived as condescending, and this probably raises the hackles of PC owners and reduces the chances of them ever even trying a Mac.
I'm a newcomer to Mac; I still have a PC and a Mac on the same network, and I know which one I'd rather use. But the old Beta vs VHS syndrome is still the crucial one. If you want universality stay with your PC.