Why is hair that is not on someone's head so gross?

I have to clean-up after teenage girls as part of my work. Whenever I sweep, the broom accumulates hair that is tangled into huge balls. The sight of it completely grosses me out. I can’t even bring myself to touch the hair without gloves on, and I always wash my hands after.

People get grossed out when they find hair in their food, but will kiss people on their heads. I’ll braid the girls’ hair and touch it, no problem, but when I have to clean their hair off of the sink I cringe.

WTF? Why is hair so gross?