Diplo, et al, you're all gay!
It's not just nerds. Every convention I've been too has had booth babes. I went to a home and garden convention and it had booth babes. Go to a car show, babes. Go to a gun show, babes. Sure, not quite so over the top and costumed, but part of the fun of these conventions *IS* the costumes, the over the top booth design, etc I went to a bioinformatics conference, and the booths didn't have model-babes hired with costumes, but you could tell that the companies choose their hottest PR chicks and asked them to dress well.
Sex sells, and advertising uses sex.
I think these conventions would be pretty boring without the "sideshow" of the babes, the music shows, the production numbers, the over the top booths.
I guess all Westerners are becoming prudes and I'll have to go to Asia to see hot booth babes, or attend Cosplay/ComicCon conventions where less inhibited women choose to dress themselves up in sexy outfits for free.
All I can say is, thank goodness for TGS, and now, ChinaJoy.