Ugh, I knew somebody would be in the comments saying this. Who cares about the ideas on offer, let's evaluate it according to the rules we all learned in third grade.
I'm going to risk moving completely off-topic, because this is fascinating. Could you elaborate further (perhaps in a new topic or blog post)?
I often visit threads and see the top-most comments being somewhat incredulous reactions to a (percieved) large number of sentiments to their contrary, so it would certainly be interesting to see at what point threads begin to evolve a critical mass in terms of which 'side' of a discussion a reply is likely to take.
I wasn't thinking of opinions for or against a position so much as the quality of the discussion. Shallowly provocative comments produce flamewars, nitpicking produces counter-nitpicking, and so on. Threads that begin with a substantive on-topic comment or two do best.