Really, no.
You don't dump 360 with PS3 even though they share so many games, so you shouldn't dump Mac with PC. They are completely different platforms. I can't see any realistic reason that they should share a category other than laziness or simply disliking the Mac.
On the otherhand, I could understand iOS working for both pad and pod, after all the PSN category covers both PS3 and PSP, but then the iPhone category would need to be renamed.
However, I will add that claiming the pad and pod share the same games is wrong. My pad has a whole bunch of games exclusive to the iPad, or, at the very least, completely different to their pod/phone varieties. It is a completely different platform, and it has completely different games.That said, the same is the case for the PSN games for PSP and PS3 -- yes, they share many games, but each also has it's exclusives.
So, that being the case, I'd now amend my request to say the following:
Can we please rename the iPhone category to iOS and add a Mac category?