I think the ads are only reflecting the mindset of a lot of standard consumers out there: "Macs are cool, but I can't afford them." If anything, these ads are only going to pander to people who are already purchasing PCs because the Mac equivalent is too expensive. Hey, I'm one of those people. I used to have a MacBook, then sold it to purchase both a gaming PC and a netbook. I recently switched the netbook for a PowerBook G4, but I'm still not out-of-pocket any more than I the amount I paid for the MacBook (a whopping $1400).
So I wouldn't knock the ads for being stupid, just for being a bit unfocused. They're not going to get many Mac users to switch to PC, I don't think. Only solidify the PCs-are-more-affordable-and-Macs-aren't-for-me mentality that a lot of people have.