So... this place isn't boring to you?
Otherwise, here's two that might fit the bill from some quick googling:
Bad Harvest: Bad Harvest is an unmoderated forum. There are no rules here, just traditions. Bad Harvest is not responsible in any way for what gets posted.
Original Trilogy: Off Topic (Unmoderated): A place to chat about things other than Star Wars. This forum is unmoderated. Reports of problems in this forum are largely ignored. Proceed at your own risk.
Beyond that, many forums offer off topic sections where users typically don't give a crap about what's in there (although many I found seem to be anti-flaming). If after so much searching you still prefer this place, why try to wreck the place when, if you were to succeed somehow, you'd be left with nothing?
Edit: Shortened the list when I saw that some hadn't been posted on in ages or were secretly sensitive despite their claims.
It's still discussion, and I am curious what the gain behind wrecking the place is.
Former spammers had more clear reasons, whether it was vengeance against Luna, Nabble angst, stress testing the place while flexing as a form of boasting through example, for the sake of parody, to enjoy suffering, or perhaps maybe be able to brag about it elsewhere. Usually they get bored and either chill out or go elsewhere, but not this one. This one instead has an unprecedented amount of patience with doing boring things while also complaining about it, seemingly doing it for no real reason beyond a chronically futile attempt at entertainment that doesn't seem to pay off even after months of trying.
This one meanwhile is going on about how the place fulfills a need, yet still aims to try to damage it. Why damage something you like when what's left after said "victory" is hollow and fleeting at best? The endgame almost seems self-sabotaging when it's not fueled by hate or sadism.