The other thing is that reddit is inherently multi-topic. You can't host hate groups and then quarantine them from non-hate groups. So what you get is a bunch of people who showed up for the hate groups also commenting hateful things in the non-hate groups. This creates problems for people who wish to have a hate-free experience to talk about their gardening projects or video games.
Will some people move to an alternative venue? Almost certainly. Will most people do that, and will the alternative venue continue growing like the old one did? I'm pretty skeptical. The reason so many communities are on Reddit is because it's relatively easy to maintain and grow a community there. By denying them that tool, you make it harder for them to do that.
I'm sure most people here who are old enough can think of some old forum they used to love that isn't around anymore. When that one died out, it wasn't simply a matter of everyone going to another one and everything was the same. It works the same way for negative things as it does for positive ones.
True but then it's not Reddit's problem. Reddit can't solve every ill, but it can cover its own ass.
You don’t sell walkie talkies to Nazis hoping that they will talk themselves out of being Nazis. You take away their voice until the bad idea dies down. Now, if you want to argue that some of these things are good ideas, I am all ears on how you’d want to justify racism, sexism, and xenophobia as valuable to our society. Unless you can successfully do that, your point isn’t valid.
Essentially it reduces the ability to detect bad actors, is what I'm saying.
Also, please keep in mind that for fringe groups like these Reddit is not their primary form of communication. That is, the community leaders don't just PM each other on Reddit or communicate via posts and comments. If there is any kind of organized effort here to effect real world change, it is coordinated by private chat, often times with assistance of anonymizing networks like Tor. Reddit is where people come into this world, but it's only floor 1 of the a vast underground bunker (for the communities where these things exist). Take 4chan as another internet dumpster fire. Anonymous periodically puts on their own campaigns like pridefall which can absolutely create real world problems. But they don't communicate through memes. When stuff starts working on that level, they are coordinating these things via better channels and that's happening today. If 4chan was to disappear, I firmly believe that core group would still be in touch and looking to set up another dumpster fire on another social media site, be it a private Facebook group, a Twitter community, a Discord server, or something else. But I'd rather they spend their time chasing their tail trying to get back to having external visibility than to have them do it in the open.
Also, they already have the opportunity to act more covertly, and they do. I am getting pretty good at spotting bad actors, but I'm sure I miss more. Some are pretty clever in their online interactions. Kicking them off Reddit doesn't give them any better tools to do this. They already can and already are doing this today.
If you want further proof of this, consider why the members of the KKK wear hoods. Could they do what they do in the open? Maybe. But because they are your neighbors, your politicians, your police officers, and your friends, they need a level of anonymity. Take that away and you make it harder for them to do what they do. Reddit provides the means for that open yet semi-anonymous MO. Taking it away doesn't mean they change their beliefs, but it makes it harder for them to do what they do.
I get it that Reddit doesn't want extremism on its site, and I don't have an opinion either way on the bans. But I think it's naive to assume that people won't just hop to another, possibly more extreme, platform.
If a bunch of assholes showed up to your front lawn and started doing asshole things, do you kick them out knowing that they might go to your neighbor’s lawn? Or do you keep them on yours to protect your neighbor? I guarantee you that you’ll kick them out and then likely help your neighbor kick them out too, not shelter them and help them do the asshole things by providing your lawn as a platform. How is this different?
All this will do is push these folks out to different platforms where they will organize brigading and bad faith participation in the dark. There are gobs of matrix/discord/irc rooms where people organize the manipulation of social media, and this move just removed visibility of it from reddit.