There is a fundamental problem with the way that MN moderates imo. I think they operate on a quick, "tickbox" approach that requires minimal thought or engagement from the moderators.
I was on a thread the other day with a ridiculous OP who was very rude and argumentative towards anyone who didn't agree with her. Someone made a very mild and fairly inoffensive statement about the OP sounding "bonkers". It was deleted when the OP reported it, presumably because MNHQ felt that it fell into the category of "personal attack" and it therefore ticked a box of not being allowed.
Meanwhile, there are many vile, blatantly racist posts which are left to stand because they don't quite tick the moderators' boxes. There is no nuance or judgement involved as far as I can tell. So if you learn to bypass the talk guidelines, you can be as racist and as xenophobic as you like, with no consequence.
I wish MN would adopt a different approach, but as others have pointed out, it may suit their purposes quite well if the bunfights are boosting their revenue. So the only option may be to vote with our feet and to alert the advertisers on our way out. Not all brands will want to be associated with the free expression of racism and xenophobia.