IMO of course MNHQ can be friendly with posters, I'm not sure it's certain posters though, they seem friendly to anyone on a thread they go on.
except when Olivias telling us all off for letting MN down!
They will also delete or pull up posters who have been here a long time if they are overstepping the mark - even ones they have previously been friendly with.
I'd been here a few weeks when I started an AIBU - that I wish I hadn't! - and a well known poster posted something that came across as a personal attack. Post deleted and that poster and I have often been on threads together - once it's dealt with it's done.
I think other posters can be unethical by carrying on disagreements across threads. But thats not MNHQ fault and I like the fact they leave us a fora to deal with it - unless we ask for help.