Take for example all the comments about how AI won't be good enough. My best guess at what is going on is HN people feel threatened by AI (they realize doing standard programming is nothing special), so they are forced to downplay it.
It's like the famous quote: "it is hard to convince a man of something when his job depends on not understanding it", or whatever the quote actually is.
Another example is when people bash (even technical) crypto posts with very generic crypto bad claims. I roughly expect someone who doesn't know anything about, e.g zkSNARKs, to comment generic crypto-bad claims. They don't have enough knowledge to actually engage with the article so they post unrelated criticism.
The last thing is Dunning-Kruger. The Dropbox story is a solid example of Dunning-Kruger at work.