I think one of the factors in homophobia is just confusion of signals. Some people dont know what to make of a homosexual. Is he a man? Is he a woman? Is he going to come on to me? If I like him does that mean I am queer? yata yata yata - a lot of social interaction is just sending small signals that reassure or offer something and thats all very tightly woven with our sexuality. Homosexuality complicates all this and people find themselves outside their comfort zones and get hostile. Not passing any judgements just an observation on how things work