Ok, I’ll play along. Homophobia is no more the irrational fear of homosexuals than agoraphobia is the irrational fear of marketplaces. Definitions change mostly because people change them but the truth is its not properly categorized and can’t be lumped in with things like claustrophobia or somniphobia.
But even those definitions aren’t entirely accurate, somiphobia is not just the fear of going to sleep, its the fear of death or nightmares while sleeping. And claustrophobia is not just the fear of small places its a fear of what the body and mind does in response to feelings precipitated from being in that small place. Each of those definitions stretch beyond the simple definition of the two words in question put together.
While homophobic is not technically the best term, at the moment its the best we have in terms of what is universally understood and responded to. And also at the moment the only people who try and defend their prejudice against homosexuals by saying “Well I’m not afraid of them.” are conservatives trying to play semantics. It’s a feeling of irrational aversion, dislike, antipathy, disgust, dismay, revulsion etc. etc. If you want to come up with a new and better word that lumps all that together than be my guest. Until then, the rest of the US has decided to go with homophobic.