It takes time for more reflective comments to appear, because reflection is a slower mental operation. Reflexive responses are much faster and tend to be generic and shallow. (https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...)

I believe this distinction is pretty fundamental to humans, so we're not likely to escape it, but the good news is that reflective comments do show up eventually if the article is substantive and the reflexive ones haven't ruined the thread. We also try to downweight the more reflexive subthreads.

More at https://news.ycombinator.com/item?id=45625084.