The support of 300 rabbis across Israel is not really a certificate of merit or honour when you consider just how many of the are primitive racists.

first of all, this is israel, and no one seems able to shut up or be willing to try to speak decently of those whose behavior or words they consider wrong -- socially morally legally politically sexually et al.
second, according to halachah as best i can understand it, homosexual behavior between males is clearly forbidden by torah, so it's ridiculous to expect an orthodox rabbi (or person) to say is isnt forbidden so, let alone to praise or accept its public profession.
third, this does not make automatically halachically acceptable calling people you consider sinning or professing publically the virtue of such, harmful or hurtful names, either individually or in groups. and yes this also refers
to all accusations against such rabbis as nazis, fascists, antidemocrats, or whatever.
and last, whatever the sin, breaking the shabbat, women wearing tefillin (not a sin as far as i know), or forbidden sexual behaviors, you do not shame them in public. period. it was not made clear the context of the rabbis' use of 'pervert', but that word goes far beyond simple homosexual behavior as such. it's the sin you condemn, not the sinner. and you do it as decently as possible.

parents and even you. Denial ain't just a river in Egypt.

They're ignoring that the biggest problem here is NOT that the rabbi disagrees with homosexuality, but rather that the rabbi used very inflammatory rhetoric to refer to good Jewish men and women regardless of whether those good Jewish men and women may have a weakness (if that's what the rabbis believe). By signing this letter, they support Sinat Chinam!!! According to the books they abide by, that's what brought about the destruction of the Second Beit Hamikdash (Temple) and I would dare say that may very well be the reason why we don't have the Third Beit Hamikdash yet.

This is just as impressive as the 100 rabbis....

Cut all public found to them and related institutions and prosecute them for hate crime, incitement, throw the book at them