I know it's not PC these days to accuse homophobic/transphobic people of being "repressed" or "hiding something" but let's consider this for a moment without letting political convenience override reason.

Something done out of ignorance is less of a challenge to dignity than something done out of malice. Therefore, biphobia from cishets is going to seem more forgiveable than biphobia from "the community" aka LGTs.

And so. Why shouldn't most bisexuals choose the lesser of two evils, while also paying back the community in kind? LGTs had a whole branch of the family tailor made to be ambassadors to the cishet community, and instead of taking advantage of an opportunity for ambassadorship, you took advantage of an opportunity to throw someone under the bus. Bet it felt good to finally have someone to abuse but did you expect them to take the abuse and do nothing in self defense?

Bisexuals have opted out. The fools you see running around with pride flags? They'll figure out the score too.