I agree with you on this point. But it can be made without using the epithet "homophobic".
You may well have a point, but I need clarification. It is not clear to me why someone would oppose that word. "Photophobia", for instance, isn't a disease so much as a state.
Besides, the way I see it rejection of homosexuality is a social disease and homophoby is just about perfect to describe it.
What is the problem with the word again?