How about this: it's a stupid term, bandied about constantly by ignorant Leftists because they think it makes them sound intelligent.
Most people, contrary to the Lefty meme, aren't at all afraid of homosexuals. Thus, it is not possible for them to be "homophobic". It's possible that a small subset of individuals may, for whatever reason, fear homosexuals, but I've yet to encounter anyone from that category. Most people just don't give a rat's heinie about them - and it's precisely that lack of regard that gets Lefty panties in a twist. If you aren't actively approving of homosexual behavior, after all, then you must fear homosexuals. Um...no.
"Don't care" is apparently not an option. You either support, or you fear. Baloney.