Because the boys look like the girls and the girls look like the boys. The fashion industry has brainwashed everyone that anorexic "bag of bones" girls are pretty.
Here is a quote from "Wit" (Maryles, Dec 26). (A girl should be like a) "hour glass...not pear...but yes...not a body that looks like a prepubescent teenage boy."
Wit however is wrong about the hourglass. "G-d made the woman small on top but wide on bottom so she can carry the baby" (Eruvin, top of 18b). The fashion industry however only picks wide shoulders. (See Nov 20, 2014)