It ends with the recognition that truth is a thing that exists, facts are real, and while there is plenty of room for debate, some things fall outside of that. That the Holocaust happened is not something we get to have an Opinion™ on. And while we can absolutely have a conversation about where that line should be, most people recognize that there should be a line, and if the goal is to create a generally pleasant online space, the line should probably be higher than "literally criminal".
I often see this idea pushed that, because some topics are controversial and politics is messy, it is impossible to actually label anything as true and all opinions are thus equally valid and should be respected. This is, quite simply, wrong. "I think you're the real Nazi" is only a plausible response if you pretend that Nazi is a genetical word for "person I disagree with" rather than a real term with actual meaning that either does or does not describe something.
DoucheAsaurus