We do caution posters to avoid AIBU if they're posting anything personal/sensitive so unless we hear directly from the OP we'd be unlikely to remove the whole thread.
Which suggests to me you are being oversensitive.
Over the years every post I have reported has always been deleted, and I've been thanked for reporting it.
The issue is, we all have a different opinion of where "the line" is, between honest / blunt / rude / bitchy.
Yes, sometimes things written down - be that a post on a forum or a text or some other social media message - can come across slightly differently from the way they are intended, as there is no tone of voice to be heard, no body language, and no facial expressions, but overwhelmingly AIBU can be blunt, but is almost always fair.
IMO, the issue is, too many people use AIBU when they don't actually want an honest opinion as to if they are being unreasonable or not, and then get very cross that their (often unreasonable) stand point hasn't been agreed with.
If you want to discuss an issue when you are low, or feeling sensitive, or you are upset, then put it in chat or relationships, and tell people you are upset, but would like an outside perspective on things. People's tone can be different then, as they are responding to what people have asked.
I also see threads disappear it seems far too commonly these days, when the OP has got the hump (there's one in my 'Threads I'm on' yesterday in fact).