The original goal of the fashion industry and catwalk models was simply to promote slim women - women who were a healthy weight. This was fair enough, and a decent goal - the happy medium. But the fashion industry didn't stop there. They became psychotic about thinness until the point where they now fetishize anorexic women who are very far from attractive and need to see a fucking doctor.
Yeah, I've heard two competing theories and I think they're both right, albeit more the first one than the second one. The first one is that when women are attractive people look at the women and not the clothes, so they wanted women who are more like a clothes hanger. Second, the influence of the homosexual fashion designer, who doesn't want to look at women anyway. (I know queers who like to look at boobs, so it's not all of them, but I also have met queers who seem to have a problem with women. It's a lumpy world.)