[cc81]

I don't think that is how they come about. It is about recruitment and ideals and how they spread not about being banned on other platforms. If they could discuss saving the white race with violence on reddit or hackernews nothing would change more than they would have more potential recruits.

[afiori]

At least something else would change. internal conversation based on uniform agreement would become impossible.

If 1% of the people on a site agree with you, you will have an harder time memeing with your buddies undisturbed.

Whether in practice the tradeoff is worth it, is another topic.