I've commented also that the karma system, as it is currently, causes less participation on the site. Just to save time I'll paste it here.

"The fundamental flaw that I see with LessWrong's main site is that its karma/moderating system has the effect of silencing and banning people for being disagreed with or misunderstood. This is a major problem. You cannot mix "I don't agree with you" or "I don't understand you" with "you will be punished and silenced."

People who spam, flame, or otherwise destroy conversation are the ones who need to be silenced, ignored or banned, and a lot of sites like Facebook have separate buttons to perform exactly that function. People in the other category, who are misunderstood or disagreed with, but who discuss constructively and rationally, are the ones who MOST need to be able to speak. I think the punishment and silencing, and the threat of it, contributes largely to any lack of new posters or threads that you might see. I know I personally refrain from posting theories or models I have that are counter-intuitive and would actually start good discussions specifically for this reason...and I put them on the LessWrong Facebook page or bring them up at Meetups instead, where I've had some great conversations and made some good friends because of it."