As with all phobias, homophobia is also based on an irrational fear of homosexuals. For most people, heterosexuality is considered the norm and other orientations earn the distinction of being 'the others', the fallen ones, or plain evil. It points to range of negative attitudes and feelings towards homosexuality or homosexual people.
The word 'homophobia' first appeared in the American tabloid Screwin an article published on the May 23, 1969 in which the word was used to refer to heterosexual men's fear that others might think they are gay.
Heterosexuals who have revulsion towards homosexuality in all its aspects could be homophobic. They go to great lengths to avoid any contact with homosexual people, and at times, express their anger and hostility by either verbally or physically assaulting homosexuals for perceived or imagined advances or threats. Homophobia can be best described as an intolerant personality disorder, and since there is no medication available to cure it, it is more of an attitudinal problem than a mental problem.
Fortunately, today, many governments have granted full rights and privileges to the gay community and they can assert their fundamental rights. What homophobic people probably overlook is the fact that just because a person is gay he may not immediately jump every man (or woman as the case may be) that he encounters.
Just as there are people in the heterosexual community who indulge in casual sex, does that make every heterosexual person footloose? It works quite the same way with gay people. So part of the phobia comes from the fear of being hit on or being propositioned by a gay person. And being appreciated is not a bad thing, is it?