I'm making a different point besides the mental health stuff, which is that i agree the physical space of a pub is a good analogy for this virtual space but it's limited.
The proprietor can choose who they want chucked out, whether that's for violating agreed norms of behaviour, just for irritating the proprietor's mates or anything in between.
There's plenty of comments made on here that would result in a fat lip in most pubs. I've made plenty myself and if you spoke to people in pubs like you do sometimes on here you'd earn a few proper doings. So the real world ways that society regulates itself don't apply in here.
You can't see the people you're communicating with. In the real world, if someone looks like they're taking a bit of banter personally and is starting to get upset, most people would stop. The real world way that people converse doesn't apply in here.
There's no real analogue for persistent dotting in the real world. There's no established standard of behaviour or even common understanding of what's meant by the coloured circles. I take them as disapproval of whatever cunty thing i've just said (or that someone likes whatever pishy tv show i jyst slagged off). Other people might take it personally as an insult and as a blow to their self esteem. I don't think that would require extreme anxiety or anything like that.
I have no idea what anyone may have done to get banned and am not commenting on whether it was deserved.
But there is a middle ground between "safe space" and "complete disregard for other people's feelings".