You're right, which is the worst part of it; realizing you are part of the problem. I think the karma system is a big driver of it, you quickly learn what you "should" or "shouldn't" be posting.

An AI comment bot trained on past HN comments that can be unleashed on the actual HN to whore karma sounds like a great meta-humorous project - it would prove that as far as upvotes go, we have achieved the singularity.