/b/ is the endgame of complete un-moderation. It performed some amusing feats along the way, but at this point it's just a wasteland.
IMHO un-moderation only works with small communities where everyone knows each other. Once you grow beyond that, you have to get involved. That doesn't mean swinging a banhammer around every day. All it takes is someone to PM people when they're going too far, lock threads when they drift too far from the forum's purpose, and generally play peacemaker from time to time.
Even when that works, the tight-knit community just loses that great feel once it gets too big. I've been through this many times.
+1 about greed, then envy, then hate... Things get ugly when money is involved, especially when it's so dynamic that people are winning and losing a lot fast. I think it's starting to improve, though the scandals will keep the bad vibes going for a while.
I hope that as the price declines the speculators and cheerleaders and scammers and the people who're encouraging and trolling all of the above will gradually wash out and we can get back to trying to make a real currency, and perhaps even an economy. It's going to take months or years of people trying to create another bubble to Get Rich Quick, or recoup their losses, but hopefully we'll get there. I'm a bear (I'll not rehash it all here, but it's all in my post history), and I hope that as BTC devalues back down toward its fundamental value (cents, not dollars), the community will improve.