This isn't democracy, this is commerce. And while there's nothing that says you can't profit from hate speech, free society generally punishes profiteers whose stock in trade deviates from accepted norms.

The fundamental issue is this: Reddit has nazis. And they don't stop nazis because free speech. But when the nazis state unequivocally that Hillary Clinton is connected to a child sex ring run out of the basement of a basementless pizza parlor, those nazis are exercising free speech, they are committing libel. More than that, they are promoting imminent lawless action by advocating that "something" must be done.

There's nothing that says Reddit needs to provide voice to nazis. "Free speech" means that the government can not silence nazis (outside of libel and imminent lawless action). Nobody at Reddit likes nazis; however, they repeatedly and consistently did nothing to proactively stop libel or imminent lawless action. First, they didn't have to. Second, they would have had to do work and given a choice between effort or rationalization, most people choose rationalization.