I think, beyond simply offering counterpoints, Lemmings are also better at accepting nuance and taking measured opinions. It would be really interesting to track changes over time in the usage of certain keywords on Reddit that would imply nuance. For instance, words like "but," "however," "think," "believe," "may," etc.
I have no doubt that the usage of these words would go down after seeing how Reddit is like now, but it would definitely be interesting to see the formal data on it