Wow very profound article. I most say I somewhat agree with your theory.
I remember that episode of Family Guy when Quagmier was a dance exercise guy, similar to Flashdance movie, and someone complained all their asses were so flat back then, that was so funny but true.
Now I'm an ass guy, but even I have to say it has gotten a bit out of hand as some women has gone overboard with the way they have shaped their bodies to look like ducks. I'm sure there is a word for that kind of body, but have no idea.
Personally I prefer the old skinny type, like Toney Braxton, Lauryn Hill, natural ass and less of the today's Nikky Minaj type.