If some set of ideas is so repugnant that quoting it, even in a rebuttal, "normalizes hatred", then why try to rebut it at all? Shouldn't it be enough to simply use social norms to shame the author into submission without addressing his arguments? Nobody feels the need to write rebuttals against NAMBLA, because we as a society live within a consensus that pedophilia is wrong.
The usual response is that ideas like the ones expressed in the "manifesto" are still widespread enough that they need to be addressed. But if a set of beliefs is that widespread, then by definition, there isn't a consensus and social norm against them. As a result, you need to address these ideas straight-up, even if you personally find them repugnant.
To dismiss them as "hatred", unworthy of being quoted even in rebuttal, just means that you've giving up on convincing anyone else to your point of view. And at some level, that's fine. I personally choose to isolate myself from people who don't believe in things like vaccines or climate change because I don't have the patience to deal with them.
But if you want to actually change people's minds, you have to deal with the fact that some people hold opinions that you personally find repugnant, and you have to address those opinions in an intellectually honest way. That's the table stakes for writing any kind of rebuttal, and once you've bought into that, there's no reason not to go all the way. In their famous debates, Lincoln thoughtfully listened and responded to Douglas's points, he didn't just rant and rave about giving Douglas a podium to speak from "normalized hatred".
That's exactly what many people are trying to do. Fortunately, some are smarter than that.
It is very pleasant and convenient to declare dominating point of view the eternal truth and any challenge to it taboo. It is done a lot by a lot of people - disagree with them, and you not just disagreeing - you are a hateful bigot and a despicable worm of a person, worthy only of derision. And that works too, especially with good peer support. The only problem with it shaming is good at silencing, but is not so good at convincing. So if you are ok with people being afraid to talk about certain topics and challenge whatever ideas are in power - it works wonders. If you want people to actually get the point, get onboard and not just be afraid to say what they truly think - there's a bit more work needed.
This logic seems an awful lot like a book-burning mentality.
"Normalization" is the process by which we treat ludicrous things as not ludicrous, but debatable.
Tear apart the ideas with friendly, well-reasoned arguments, yes! Ideas are fair game. Fight fire with fire, not gasoline.