Why do sometimes some guys reject the girls they like?

I’ve had multiple relationships in the past where men (that have told me they really like me) would just throw me out of their lives, move on, ignore. And then after months when things are settled I would talk to them and they’d say they actually liked me a lot but couldn’t deal with the frustration.

What are some other reasons why men could reject the girl they are falling for? Or hate on the person they like?