The word homophobe does not appear in my 1975 edition of the American Heritage Dictionary. My computer dictonary, however, defines it as: "an extreme and irrational aversion to homosexuality and homosexual people." The word as so defined was first coined by clinical psycologist George Weinberg in 1969. As such, there can be no doubt that it was an invented word with an ideological purpose. But as ideologically charged as the word was from its origins, it's interesting to see how its usage has changed over time.
My best recollection is that the word was first commonly used to describe the truly irrational practice of "gay bashing" , where, usually, young thugs would prowl the inner city streets and target soliciting homosexuals for mugging. The accepted rationale for this phenomenon was the thugs' raging hatred of homosexuals. This certainly fit with gay rights activist's agenda of promoting greater social tolerance of homosexual behavior. I'm unaware, however, if a study was ever done to ascertain whether the motive, in the majority of such cases, was really hatred of homosexuals, or the perception on the part of the muggers of soliciting gays as effeminate, making them unlikely to resist and thereby easy victims of violence or robbery.
These days the word homophobe, and its derivatives, homophobic & homophobia are used like scatter-shot from a blunderbuss, an all-purpse accusation to silence not just any argument concerning the morality or respectability of homosexual practice, but also to punish and socially condemn anyone who refuses to celebrate the beauty and virtue of another variety of expression of human love. The fact that popular culture--academia, public schools, mainstream news media, and even television situation comedies--has so thoroughly embraced this idea, all in less than a single generation, perhaps explains why those of us who are advocates of traditional and religious morality are at a loss to come up with a vocabulary with which to argue our side. But of course the genius of this wordsmithing strategy by the gay lobby is that even if we had a lexicon for our argument, we wouldn't be able to use it. No matter how reasoned, dispassionate and authoritative our case, it would not be acceptable; it would not be viewed as a legitimate debate, but rather the ravings of the mentally unstable. To gay advocacy, disagreement with them, or refusal to socially endorse and even celebrate the legitimacy of homosexual practice is not fair argument: it's neurosis.