Some of the web comics I read have LJ feeds, and some of those tend to acquire a lot of comments.
But even as innane and silly as I thought some of those comments were, I didn't realize I was so spoiled. I just went to another web comic's forum (trying to make a connection between a current comic and references in past comics) and was shocked and suprised (saddened, even) but how... very silly and innane most of the threads were.
Of course, I started wondering 'What's the difference'? The webcomics I am thinking of on LJ are things like Girl Genius, Something Positive and XKRD (where people that claim to hate the comic still come to read and bitch. Go figure.) and the comic I visited the forum for was Looking For Group. So, is it a LJ versus forum thing, or a genre-of-comic thing?
I am leaning toward the LJ versus forum, as I have to ask myself 'And how many forums do you still read and why did you quit reading them? Oh, right, the juveniles."