In some ways it is better and in some ways it is worse.
Threads in AIBU these days are just ludicrous, there are a lot of po faced posters around who pop up on threads that are quite clearly light hearted doing their faux offended routine, way too many trigger warnings, too many trolls, made up rubbish and weird creative writing styles.
But
There was definitely a closed shop feel to MN a number of years ago, BIWI described it well as a Head Girl/Prefects clique. When I first joined and lurked there were numerous threads where a poster would ask advice, poster A - new poster, not well known or part of the clique would give advice, members of the clique would join the thread greet each other and set up a virtual buffet whilst chorusing "OP wait for Poster X to arrive they will give you the advice you need", Poster X would duly arrive and dispense their pearls of wisdom which would be exactly the same advice as Poster A had already given and then the fan girls would spend the rest of the thread swooning over Poster X.
About the waving and greeting, doesn't bother me but I can understand why new posters got fed up of it when entire threads were taken up with people waving at each other and talking amongst themselves completely ignoring the OP or any new posters who dared to venture onto the thread.
However, there are/were a group of long term posters, a number of them on this thread and some who for various reasons are no longer on MN and are much missed, who don't and didn't treat new posters as outsiders to be ignored or belittled.
The Feminist Chat Board is excellent, inclusive, full of intelligent and interesting debate and for me personally the best part of MN and it manages to be so whilst under heavy restraint not applied to any other board of MN.
I found the melodramatic reaction of some posters to the NYE debacle hilarious, the way some of them carried on you would think MNHQ had asked them to sacrifice their first born. Some of the early/original posters seemed of the opinion that MN was their site and treated it and new posters accordingly.