Nobody puts him in jail. Nobody takes away his right to make a living or his children or his home. They just send a clear message: Don't bring that sort of thing around here. Don't bring it around us. There's no point in engaging in a dialogue with that person. Sure, you allow them to speak, in that you don't respond to that speech with violence or prosecution. But you don't have to make room for it.
We can't and shouldn't have the government stepping in to say what speech is or is not allowed. And in the United States, we don't. Russia is another matter, but as the post says, the idea that that means every Russian person or company is OK with things this awful is not true.
What that means, though, is that if there are sentiments so odious (and in some cases, literally dangerous, but not illegal) that our free society doesn't think it's appropriate to support a venue for their discussion, it's up to that society writ large, not government, to limit that discussion. There is nothing wrong with fostering a societal sense that there is no room in our world for the kind of shit that Kiwi Farms spewed, even if it is legal. There is nothing wrong with expecting large companies to live up to that standard.
So I don't see this as scary, at all. I see it as a relief. I see it as a free society working the way it's supposed to, with some caveats. (I still don't love how much power large corporate entities have, but not for this reason, exactly.) And I think there are a lot of people out there whose lives are safer because of it.
Edit: For people who haven't seen it, here's the scene I reference: https://www.youtube.com/watch?v=TXlHKTPfLVA