Why are some guys so mean in highschool?

I cant figure it out, some guys are just plain rude and ignorant. I have a few close guy friends and they certaintly dont act like that. like for example those idiots were rating all the girls bodies in gym like....ohh shes a 9, no 7, and omfg shes soo fugly shes a 1. and then they screamed 8 at me. im like wow, im not a freakin number! i mean i cant believe im saying this but they were better in middle school. well for the most part. all they care about is a girl being like something to put on their arm. im like wow....i dont blame them for wanting a pretty girlfriend but please looks arent everything. it was sorta funny thought beacause half the football team thought none of the girls in our school were "hott enought" to go to homecoming with them. geez