As for blame. I agree that all involved share blame. And you, what culpabilty do you accept? (I've tried to word this civilly, it just doesn't read as anything other than hostile, it isn't meant as such, take the following as the bad orator that I am). Someone deriding purity politics wouldn't suggest they're pure in the situation. (Again, not intending to be a dick... I just can't figure out a better way, seems like something to put into an llm and get it reworded... I dunno)
I'm suggesting the culpabilty you accept (I suggested at the time and now) was getting angry at the vegans, constantly hate posting against them instead of pushing leadership to plan with, for, or around them. In effect, I'm pointing out you punched down, not up. The vegans have less power than the animal rights group leaders, if you can't make the leaders close the puppy farms, at least make them stop supporting puppy farms.
You can't force voters to take blame for something they don't want to (look what a bear of a time I'm having with you). Certainly not with memes. It takes an involved, and I hope like this one, empathetic conversation to do that. That's just people... They don't play the ultimatum game the way the game theorists said they should, that's just people. some people have hard lines and genocide isn't an unreasonable one, that's just people.