Well, FWIW, I think AIBU is fine. If you don't like it, hide it - it's not a difficult concept.
Last month when certain people were complaining about it (yet again) there was an interesting debate in there re rear facing car seats & how safe they are etc, it was interesting... but no, it got moved to 'car seats' where unless you are buying one and want the boring questions answered (will it fit my car) no one reads.... a good debate lost because it was about a car seat.
AIBU is a general, robust, topic. If you don't like it, post in buggies & lentil weavers unite
If you change AIBU there will still be threads about MIL's, P&T parking & DH's being idiots... chat would do fine, but it's nice to have a 'robust' area and a 'gentle' area.
MN has a lot of topics to choose from, choose the others & hide AIBU if you don't like it. It's like going into a restaurant and complaining there is steak on the menu, choose the fish - ignore the steak.