Gees, I get so tired of hearing people say this, so pardon me for the all-caps, but...
APPLE ALREADY TRIED THAT AND IT DIDN'T WORK.
Remember the ads with the guy on the airplane? There were others like that too and many, many more before where Apple tried to show why the Mac was better and there isn't a shred of evidence that such an approach ever made a dent in the Mac market share. In fact, those ads appear to have produced the opposite effect.
On the other hand, Mac sales have been steadily going up over the last couple years and the more they attack Windows and PCs, the better they seem to do. How can you claim the PC-and-Mac or the switcher ads were not the way to go when they are showing results?
Ads have to play down to the lowest common denominator. They have to be written for monkeys, couch surfers, the short-attention span MTV generation. They have to entertain, catch your interest and get people talking. Like it or not, these current ads do that. 30 seconds of showing how awesome stacks or Quick View is... well, I kinda doubt that's going to get the sort of reaction Apple's marketing people want.