Because instinctively, most everyone knows that homosexuality is inherently disordered. We even have evidence that such gut reactions to homosexuality are inborn or hard coded.
The only two ways that the LGBTQ was able to obtain any sort of tolerance or acceptance was via their supposed underdog status, AND by constantly browbeating people with the propaganda that sodomy acceptance was a really really important civil rights issue and that only evil people and primitive dum dums could oppose anything that the LGBTQ rights movement was fighting for. And cancelling anyone who resisted.
They had to do it, because again, hatred of the homosexual act is a deeply ingrained instinct, and the LGBTQ needs to force the majority to suppress their gut instincts on the subject in order to obtain anything resembling mainstream acceptance.
Though I cannot help but note the irony that the gay rights movement essentially employed some form of "conversion therapy" against "homophobes." Or in the very least, what they would consider to be "conversion therapy" if the positions were reversed.