I'm another who is used to more 'robust' boards, and on the whole find GN more polite than not. There is, IMO, far more passive aggression than outright aggression on here, so I was quite shocked at some of the posts around the time of the GE as it was very out of character for the GN I know.
Re the right and left thing - I don't think I have seen extremes on either wing on here. There are Labour and Tory voters, (and now those who intend to vote Reform) as well as Greens and Lib Dems, but not much (if any) Fascism or Communism. I suspect that most people see themselves as reasonable centrists, and therefore anyone who leans one way or the other more obviously than they do (or think they do) is a 'loony leftie' or on the 'rabid right'. As a generalisation, I think that there are people on both the left and right who are given to authoritarianism. The difference is that on the left it is usually more about theory and dogma (hence the long explanations and requests for evidence) and on the right it is more of a 'because I/he/she say(s) so' and a belief that the speaker 'has the facts' so there is no need to provide any. Anyway, we still have democracy, which means we have to live with the fact that others disagree with us politically.
I also think that there can be a tendency for people to think that any disagreement with their point of view is a personal attack. Disagreement is not personal, and I sometimes wonder if those claiming it is ever have discussions 'in real life', or if they just expect to have the last word.
Generally, I am in favour of leaving nasty posts for others to see. They form a picture of a poster and others can see for themselves what they are like. If posts are deleted nobody knows if it is because of an over-zealous reporter or because the post really was a personal attack or whatever. I do feel that whilst there are posters I miss, HQ can't allow some to stay because they are popular and ban others for lack of a vocal following. There are others I miss who have left of their own volition because of what seems to me obvious hounding by people who are never pulled up for their behaviour (or don't appear to - it's impossible to tell).
I think a lot of the problem is that the 'rules' are so vague. 'The spirit of GN' is meaningless, and there is no obvious protocol for what happens if someone is suspended or banned. I realise that if a first offence is particularly awful the mods have to act, but I'm talking about people who routinely upset others without crossing into illegality. HQ have posted that there are talks behind the scenes and various stages before someone is banned, but they don't explain what they are or how they are implemented. It would also be interesting to know whether posters can be banned for vexatious reporting, although anonymity would make that tricky, I suppose. We know that lurkers also report people they don't like. Does HQ check the posting history of a reporter before adjudicating? It seems daft to act on the sayso of someone who contributes nothing but wants to get a regular poster banned.
