Cardinal says: "Ballet choreographers and fashion designers are as much to blame for this phenomenon as the designers of the doll itself."
Ballet choreographers? What? Have you ever looked at a female ballet dancer? Ballet dancers do not have large breasts and commonly have waists the same size as their hips -- I recall a production of "La Bayadere" (The Temple Dancer) where the harem-style costumes had to have skin-colored straps attaching the pants to the tops, because the pants would not have stayed up by themselves. (No hourglass figures there.) They are thin because they practice constantly, hours every day (female runners are thin too) and usually short so that they won't be taller than a male partner when on their toes (a major annoyance to me). But they have dancers' muscle -- no "about to pass out from hunger" look -- and a large-breasted ballet dancer would have trouble finding a part; ballet dancers are traditionally supposed to look like fairies who don't really need to touch the ground, not sex symbols. In short, ballet dancers look absolutely nothing like Barbie and most would not get high ratings on Am I Hot Or Not for their figures, or ever appear in Playboy.
(added later) Women who've fallen prey to heroin chic only superficially resemble ballet dancers either, I think, but the parallel is closer. Ballet, however, in common with most physical sports, can lead to women doing anything to be thin, because extra flesh to move is a liability for flexibility and speed. However, a dancer who starves herself wouldn't get far -- she'd pass out on stage, if not earlier at rehearsal.