Many of my friends signed up. There was never hateful or violent rhetoric in their feeds, nor mine.
You can be removed from these platforms at any time, with almost no appeal. That's a significant flaw, not a design feature. Like it or not, Facebook and Twitter are the public square for the Internet now. I don't personally like it; I hate it... but that's the way it is. Maybe that's the problem. Maybe its time for everyone to build their own website, host their own video and audio, etc.
I agree with you on censorship and honestly there's no right way of doing this. What if someone in a certain position used Twitter to call for another gathering to "save our country" fight and show "our strength" and then we have dead senators and army boots in the ground? You can say we want no violence right after saying "fight like hell for the country" but... Maybe a timeout was the lesser of evils?
Intent matters. Did FB purposefully tailored their site's pitch for such characters? Did they have enough mods to delete stuff or algos in place? I suppose in groups barely anyone would report posts as not appropriate.