Why do guys make fun of ugly girls?

So most of my life ever since I was in middle school I was always made fun of or called names for no reason. Never had many friends or guys that liked me for that matter. I got called annoying a lot which is odd cause I never spoke to anyone. Was always told im ugly even though I tried to look nice as I could but wasn't very beautiful compared to other girls. Never really got asked out just left alone reading books in my room.
Why do guys make fun of ugly girls?
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