Just compare the average discussion on /pol/ to the same discussion on /leftypol/. There is a reason the Left Can't Meme. Even on the media, there are far more jokes towards Trump during his campaign than there were towards Bernie Sanders despite them being ideological opposites.

Reactionary conservatives don't care about political correctness at all. They often use the bluntest and most offensive language. Progressives on the far-left are a lot more verbose which makes their ideology harder to digest.

Fascists and extreme libertarians are more restrictive of censorship. Leftists delete comments or even ban anyone who seriously questions their ideology. Libertarian boards on the other hand almost never ban people or delete posts unless the user is a very obvious troll that is spamming the website. White Nationalists would probably be more willing to censor dissenting opinions if they had more power, but since everybody hates them they actually tend to be more sympathetic to those with controversial opinions which makes them less ban-happy.

Extreme progressives propose more hypothetical ideas for society like total socialism or complete freedom in identities. The far-right on the other hand wants either a completely free market with no government at all or an oligarchy that restricts rights on gender, sexual, and racial minorities. There were plenty of examples in history of both fully laissez-faire economies and oppressive countries that persecuted people so their ideas are both more palpable and more threatening.

the far-right often attack the sacred cows of liberals like non-Whites, LGBT, young women, etc. which leads to outrageous reactions. The only sacred cows conservatives have are gun ownership and Christianity. Gun ownership is mainly a legal issue and mocking Christianity doesn't generate a lot of controversy due to the rise of irreligion in general society.