Harassment isn't. One of the big points of the article is that when law enforcement doesn't act that is justification that the action is legal and thus "free speech". Except that law enforcement almost never acts against online harassment. There are plenty of laws restricting free speech when it harms others, and I'd hope you agree that some of the examples in the article crosses the boundary into things that should be criminal.

Well, this right does not imply that everyone or even a certain service provider has to provide you a platform for it.

Free speech, sure. But freedom of association, too. And accepting the consequences of one's actions.

If misogynists and abusers want to go and construct their own forums, nobody can legally stop them (as long as their discussion stops short of the various sorts of criminal speech, like conspiracy to commit). But nobody is legally obligated to support them, either.

Reddit tomorrow could say, "Welp, we're not going to host people who cause harm in way X". And that's perfectly American because they'd be exercising their own rights. That they choose to support abusers is legal, but it is well within everybody else's rights to point that out, with volume and at length.

And it has almost nothing to do with reddit.

Reddit could censor all instances of discussion featuring the phrase "hackers news" tomorrow, and it's not as if they would be brought up on freedom-of-speech charges.

And like all religions, it ultimately becomes harmful.