I take issue with both of your claims!

Sure, wit isn't rationality, but I suspect it can be quite the rationality enhancer.

And I assign high probability to the existence of a "long post bias", though I'm not sure it's higher at LW relative to other places. It may not be a bias, though; Paul Graham, for example, says that long comments are generally better than short ones, and this seems to be obviously true in general. In terms of posts, I'm not so sure. I would have upvoted the grandparent comment of this if it weren't rude (how hypocritical of me).