Not nonsesnse as in whimsical things, take a look at the threads about the missile silo and paintball wars, you'll see it's a pretty free place to post in. Nonsense in this instance means, or I beleive it means anyway, pointless screaming and insulting, and bitchin as well.
The point of the forum is to have fun, to exchange opinions, to learn new things. NOT to sit around just screaming pointless things at eachother.
Lame? Maybe for some, but for those of us who think that "flaming" is about the lamest thing a person can do (after all, we're on a forum, you can always calm down before posting replys, noones twisting your arm to yell back in anger) it's a nice place.