I don't disagree with anything you written, I just don't know that there's much to be done at this point. Words mean with they're received to mean, not what their roots lead one to believe they should mean.

Homophobia has been in common use for decades, and its meaning is widely received not as "irrational fear of gay people" but as "personal prejudice against LGBTQ people."

Maybe we should have a better, more accurate word, but that would require people to start using that word and having the word take off and gain popular traction.

I've seen plenty of proposals over the last decade or so, but I haven't seen anyone actually using an alternative like their heart was in it, let alone people copying them and making the alternative viable.

From a linguistics perspective, vocabulary change in a language is almost always a bottom-up phenomenon. Sure, it's possible to coin words and change the meaning of popular words, but the process is usually popular rather than planned.

So, if we replace "homophobia" with something different, then it will probably happen while nobody's looking, in the sense that people will begin using the alternative fairly spontaneously, because they heard it,it appeals to them, and they want to adapt it.

That's how homophobia got to be the default. People heard it, liked it, used it.

It's hard to plan for that. Most planned coinings fail to catch on. "Homophobia" isn't a perfect word, but it works pretty well, and I haven't sensed any popular support for an alternative yet, possibly because the alternatives people offer seem to have their own, different drawbacks.

"Heterosexism," for example, doesn't have an obvious meaning. It could mean prejudice against straight people. Also, it leaves gender-variant people out of the mix. (Yes, technically homophobia does too, but it's adopted already and has cultural inertia.) So, as a writer, I would find "heterosexist" awkward and hard to use. I'm not saying I wouldn't use it if it caught on, I'm just saying I would feel uncomfortable unless and until gained popular support and a clear received meaning.

As to helping push for a replacement, I haven't seen anything I'm excited enough to want to push.