To be honest I think what you did on the question was enough and the right thing to do:
You explained clearly and plainly in a straightforward way why that's a false equivalence:
However, your point that "'All Nazis should be destroyed' is the same thing as stating that 'All Jews should be destroyed.'" is incorrect at a fundamental level:
The Nazis wanted to destroy all Jews, Gypsies, Slavs, etc. based on their "race" (i.e. the ethnicity they were born into.) Being part of one of these groups was not a choice, and it extended to women and children. In other words, genocide.
Affiliation with the Nazi party was a choice, and although I doubt that all German soldiers were enthusiastic supporters of the regime, it was their ill fortune to face conscription in service of the Nazi agenda. Nevertheless, we are talking about soldiers and politicians, not civilians and children.
Presumably, you're also one of the six people who downvoted it, and that's totally fine.
Anyone reading the question will see your answer which contains a very good explanation of why that's a false equivalence. They'll also see that the community didn't like this question, and the comments and this answer explain why.
Hopefully the person who asked it learned something too.
That's a good result.
If someone seemed to actively be using this site to promote an agenda or excuse any crime like genocide then it should be edited out or, if there's nothing more to the post, deleted, with possible sanctions like bans against the user because it's an abuse of the site. There isn't clear deliberate bad intent here though, it could be that they genuinely didn't understand a point about a film, and asked a question (albeit an unclear and confused and rightly closed one) about it in a way that showed up a fundamental misunderstanding about history (as well as about Tarantino's approach to anti-heroes).
The question was edited to be less of a rant/opinion piece and the asker's misunderstanding was corrected by you, rather well.
People come to films with different levels of understanding of their subject matter. I could easily watch, say, The Killing Fields and then accidentally ask a question that was offensive to Cambodians, with no bad intentions, just inadvertent ignorance of the nuances of the subject matter. The best response would be to explain why I was mistaken - like you did there.
Good job well done.