There are a lot of terms we have for people who harbor prejudice against others. Racist. Misogynist. Antisemite. &c. I think most of these terms are overused, because our culture confuses self-righteous name-calling with “advocacy.” But they can still be useful words. Some of them, however, are just bad. “Homophobia” is a prime example.
“Phobia” is a technical psychological term referring to an irrational and debilitating fear of something. Arachnophobia is the irrational and debilitating fear of spiders, claustrophobia that of enclosed spaces, etc. Homophobia, however, is not the irrational and debilitating fear of homosexuals. We use the term to refer to a prejudice, rather than a psychological condition. This creates the subtle implication that prejudice against homosexuals is a psychological disorder and not an ideological one, which is dumb.
Moreover, the idea that prejudice against homosexuals is necessarily a fear of some sort is preposterous and unhelpful. For whatever reason, we have linked hatred with fear. This is a bad idea, as it suggests that we should try to combat hatred in the same way that we do fear, i.e., through gradual exposure to the hated/feared stimulus. This is how psychologists treat phobias. If you have Arachnophobia, then you will gradually be exposed to images of spiders until you can look at a real one without fainting, for example. But people who are prejudiced against certain groups don’t necessarily become less prejudiced after exposure to those groups. This is because what they feel is disgust, not fear.
Suppose, then, we create a word to replace “homophobia.” This will take care of the problems above, but I still think that most uses of the new term are likely to be misleading if not completely wrong, given the way that “homophobia” is used today. I most often see the term used to refer to people who hold political positions that are culturally conservative, especially with regard to same-sex marriage. This is wrong.
It is possible that opposition to same-sex marriage is sometimes motivated by prejudice against homosexuals, but not necessary. You can believe that it is immoral for men to have sex with men without being prejudiced against homosexuals. You can believe that the institution of marriage is about more than personal fulfillment without being prejudiced against homosexuals. The first belief is one concerning the morality of certain behaviors, and the second is one concerning the nature of marriage itself. Neither beliefs require a corresponding belief in the inferiority of any class of persons.
This is what LGBT advocates (and people on the left in general, it seems) often fail to grasp: One can oppose policies aimed toward advancing certain identity-groups’ agendas without being prejudiced against those identity-groups. Contra Foucault and his minions, not all classification is an attempt to subjugate and oppress. The way we understand sex and marriage has implications for the health of our society, and we want to get things right.