it isn't limited to AIBU.....i've seen it happen in a lot of boards.
Some posters don't like what you say, or the truth hurts, so they'll start accusing you of being a troll/goady etc, and then get other 'friends' of theirs to pile in as well.
Some of them will even go and read your previous threads/comments and then say "oh, you always do this on other threads' and they'll give their twisted examples........so when you try to explain your point, or even correct their bullshit - it's YOU that gets deleted/banned from posting...for 'breaking Talk guidelines/trolling/being goady'.......even though an amoeba could tell you who the actual culprits are!
I definitely think MN admin has it's 'favourites' and personal prejudices.
It most definitely is not 'one rule for all'.
Were you here when there were ding-dongs going on with a poster who was the aunt of a One Hit Wonder?
That was HILARIOUS....there was a group of posters who behaved like mean girls at school - star struck mean girls.
Anything X said was agreed with and they all fawned over the poster like bitches in heat 
Seriously - if anyone dared to disagree with her, criticized anything she said or questioned her 'expert opinion', they were pounced on by the Desperate Mean Girls.
Cue mass 'reporting' of the 'dissenters' and getting people banned.
Not ONCE did i come across MN admins pulling up posters like them.
Makes you wonder what kind of lives these people lead to be that desperate to be that intolerant.
The other thing i've noticed is how quick some posters are to dictate how you should present your view/opinions.
Like there's only one way right? 
You can't ever be blunt, frank or judge for yourself whether a situation needs a soft response or some straight up reality.
Oh, and if you have ASD you must declare it whenever you post an opposing viewpoint or enter into a debate -otherwise you're 'drip-feeding' and 'making excuses' when you try to explain why you're conversation style is different to theirs.....but don't forget you're still in the wrong cause your ASD means you can't possibly understand what they're going on about.....
Doesn't put me off though - i've dealt with tougher things than keyboard warriors 