i would say stupidity and shyness.
i fully acknowledge and agree that looks are almost everything. (and that has not worked in my favor as well), but i would say in my case, mostly stupidity and shyness.
i was just thinking about this today: i remember at a 6th grade dance, this girl wanted to dance with me and a lot of the other boys and girls were trying to get me to dance with her, but i just wouldn't/couldn't do it. She was the popular cheerleader type. Good personality too---wasn't stuck up. That's like someone trying to give you gold.
How fuсking stupid can you get?