Comment by abcd_f
You can see a form of this effect on HN itself, in particular in Show HN topics.
First few comments basically set the tone of the discussion and its dynamic. If they are shallow, negative or dismissive, the discussion gets stuck and takes a while to recover even if the submission has a lot of actual merit.
On the other hand it can recover. I am not going back to reading sequential pages on a forum. Good enough until something better comes along.