Sculpted ribs won't make a bit of difference in the fit of the clothing. And Jekka wasn't complaining that the mannequins are a size 0, but that their ribs are too prominent. That's not healthy on anyone. And I'd wager a bet that she's not jealous of women whose ribs stick out.
I'm not saying your argument about obesity has no merit, but it has nothing to do with her point. Unhealthy is unhealthy, be it too skinny or too big. You keep talking about how it looks to you, her argument is about the unhealthy body image it projects. Two completely seperate topics.