I've just read through all of the threads featured here and holy stuff.
What about the BLFs makes it a magnet for weirdness and drama?
It's probably the lax administration. Most forums will ban you for being an starfish, and obvious alts aren't allowed. If you want to be a total stuff, then pay your way back in, you can - and that probably attracts a lot of people with poor social skills (who want revenge or whatever) or have more money than sense.
That, and Blockland is the type of game you'd probably buy your kid. This forum has a pretty sizable 12 year old population at any given time, or at least it used to. Middle schoolers aren't known for being calm and controlled.