Both Reddit and Twitter were basically free for alls until 2015 or so. Their user numbers were growing strongly. So I don't buy the whole offensive speech is going to drive off users angle. Spam is a different story, but Elon Musk has never said he is going to allow that.

Why not allow spam? Surely the marketplace of ideas should be as free and open as possible?

Holy shit ban this troll

Hardly. The point I'm making is that any platform with user supplied content must have moderation of some speech. No platform can exist totally unmoderated at Twitter's scale.

So then the discussion is about where you draw the line, what speech you permit and what speech you prohibit. Apparently, there is a community of folks who believe Twitter should allow racism on the platform, despite it currently being disallowed. I think it's more than fair to say, "if you are allowing speech most people would find offensive and was previously banned, how far are you willing to push that needle?" Bigotry is one thing, but what else is on the table?

Elon Musk has repeatedly indicated he believes in free speech and the marketplace of ideas. I think it's more than fair to ask what his limits are.

I'll hazard a guess that since Reddit is at least vaguely self-selected topical, it's possible to evade a lot of the stuff any particular user doesn't like. I personally read some technical reddits, some palaeontology redits, and a few "metro" reddits that are near where I live. I've never seen the amount of puzzlingly irrelevant ads, bots, spam, racism and fascism I regularly saw on Twitter (I've deleted my account).

For Twitter, you get what the algorithm selects for you. Clearly that algorithm has some cut-outs for advertising, and particular accounts, and after that, I won't hazard a guess. But it's not topical the same way subreddits are.

I expect that Twitter will at the very least trim crypto scam spam, especially bots that impersonate Musk himself. Would be funny if this issue stays unsolved.