This has happened to me 2x in my life, both with men who were very sensitive and coming out of failed marriages (if that has anything to do with it).
Besides the obvious "finding another girl", are there any other reasons where you find it normal to completely avoid someone, especially someone you really started to care for who tried to keep in contact. Is it really that hard to respond to someone being nice? I never find it that hard to respond to people even if I don't want to be with them.
PS is there anything you can do to get through to these guys?