Oooookay. Prepare to possibly be offended.
So, when I first joined this site, everybody seemed pretty cool. No overreacting, no hating, no (well, not much) immaturity... Of course, that could just be because I didn't pay as much attention back then as I do now.
Then chat got removed. I don't know what happened, as I wasn't really a huge part of the whole chat thing, but people were mad. So many problems happened in the course of a few months. Feld0 basically abandoned the place, all the other mods and admins disappeared, the whole SpamBot war, the forums breaking as a result of Poniverse... One thing led to another until everybody started hating on Feld0. It didn't stop at Feld0, though. Oh, no. Nintendo haters started to appear. The Nintendo lovers would bash on them (me included, sorry D:), and it all eventually led to everybody constantly being sarcastic and insulting each other for no reason. I like to think that I kept myself above it all, but I spouted my share of sarcasm, too. ...Anyways... Then some users (I won't name any names) started to abuse their ability to work around the rules and filters of the site. Signatures were filled with insults (indirect, I'll give you that, but insults) directed at users, Feld0, and the state of the whole forums alike.
So that's basically where things stand today, or that's how I see it...
As for how we can fix it, I have no idea, other than essentially performing a hard reset on the site, erasing all members, posts, everything, and then letting the userbase slowly fill back up with those of us that still want to be a part of the site. It's a crazy idea, but it's really the only way to clear out all the filth that exists here.
Of course, there would have to be a new set of RULES to keep this ordeal from repeating itself. No swearing (white swearing could be tolerated, but come on, this is a website for discussing a Nintendo console. Kids are bound to show up.), no innuendo, no hating/insulting (of course, arguing would have to be allowed; the whole purpose of the forums is kind of to discuss and debate things about the Wii U), etc. And we, the users, would have to have the responsibility of reporting any posts/members that broke these rules.
But ultimately, we have to stop hating each other. We'll never get anywhere if the whole of the forums is pitted against itself in a battle of insults and superiority. Over on the MLP Forums (please don't hate me for mentioning its name here), people rarely have a real disliking for each other. Of course there's some playful banter and teasing between members, but not so much outright and sincere hostility as there is here. It could just be that there's so many members there that I just don't notice it, I suppose, but that doesn't change the fact that these types of thing do happen here.
I know you said not to say "let's ban so and so", but there are a few troublemakers here, and I'm not saying they need to be banned, but they should be at least warned. Possibly punished in some way. They just need to be told that if they don't get their act together, there will be blood consequences.
Anyways, that's my theory and I'm sticking to it!