The author makes other mistakes too such as thinking history that was already written is an absolute truth when it's actually something subjective written by the "winners." I lived through that once, the history that I was taught as truth in my school many years ago was proven to be false a few years ago and the lies were based on what today you'd consider hate speech.
I think the moment we can solve detecting hate speech using a machine will be the same a machine can pass the Turing test because it's impossible to define hate speech in objective terms. Meanwhile we have two equally incomplete solutions: allow all speech or let some people subjectively censor things. Neither of those things will satisfy the author of this post (well maybe the latter will).
History is written by the winners, however, even if the Nazis had won the war, I think people would still understand that discrimination against any particular group is wrong. Who knows?
Censorship isn't something I stand for. However, in the UK I can be vocal about my opinions as long as I'm not harassing certain groups for no reason. Sure, thats censorship, but I can speak out against my government without showing hatred if they were to take the policy too far. Its a fine line.
I think that had that been the case the people who remained alive would be people with ideologies aligned with Nazism and would consider discrimination against a particular group the right thing to do. Of course there will always be people who stand against the winners, real life proves this: Nazis still exist.
Sadly, they always will. There will always be people with ill intent in this world, because the world isn't perfect. However these neo-Nazis use free-speech to get a voice that they otherwise wouldn't have.
Hate does not exist in words. It exists in the mind of the person using the words. And we can never know what is in that mind without knowing the person on an intimate level. Until we all understand this, all this noisy anger and offense will never end.