The bar for a one-liner joke like that to count as substantive is high—it needs to include something genuinely new and clever or else it's just internet fodder, and will encourage others to make even worse posts. The GP comment was way too obvious and predictable to clear that bar, which is why it led to a lame subthread (mostly now flagkilled).

The gold standard HN explanation about this was by scott_s many years ago:

https://news.ycombinator.com/item?id=7609289

https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...