If these forums are renowned for anything, it should be that!
As for the being mean to new users, well, it is amazing how many new members suddenly wish to join when a new competition is running and the criteria for entering is so easily attainable. Yeah, I joined here after having been on MyBB forums for a while and then saw the Red Dead compo, but 6 months later and 1200+ posts later, i'm still here. People should also learn to take things with some salt.
I've seen regulars here get slated badly on certain topics and called out on others, but like big boys, we carry on with life. I've seen some guys get into it quite heavily today and tomorrow they are cracking jokes at each other. As somebody once pointed out, it is the internet, get used to it.
If you want to see some forums where the members see themselves as Gods and completely decimate new users, go look at the SAIX forums, specifically the Battlefield sub-forum.