To everyone asking "why can't we just tolerate their opinions and let them say it?" I highly recommend to read up on the "Paradox of tolerance" from Karl Popper. The TLDR verison: " if a society is tolerant without limit, its ability to be tolerant is eventually seized or destroyed by the intolerant." Because it is contradictory to extend freedom of speech to extremists who - if successful - will ruthlessly suppress the speech of those with whom they disagree.
Anti-semitism, or any kind of racism, homophobia,... these things have no place and there is no reason to tolerate such views just for the sake of "free speech", with the conseuqence of people getting hurt, killed or democracies getting overthrown or <insert other worst case dystopian scenario here>.
Also one should never forget, that the holocaust comparisons, as in comparing it with e.g. getting negative twitter feedback for your shitty worldview, is a common propaganda tactic of the radical right / Neonazi groups and the step to holocaust denials, as it belittles/negates the horrors of it. "We are the new jews" are the famous words of a Neonazi party leader in Austria, when he made a statement to the press when he was confronted with pictures of him "Sieg Heil"-ing to his neonazi comrades.
There will be no acceptance for this kind of shit, never again.