On a related note is the distinct lack of ass in anime. They'll have tits bigger than their heads but have sad flat pancake asses and skinny chicken legs and it looks weird and imbalanced. There's a big (pun intended) market for bunda that they're letting go to waste, just look at how people drooled over 2B.

And on your point I can hypothesis that Asian just prefer petite women the way Americans prefer curvy women, and that said preferences can get...uh...exaggerated. At least that's the only logical way I can get my head around it. Personally speaking I mentally file loli stuff in the same folder as furry stuff: I'd really rather not see that shit, but that's nobody's problem but mine.