"I don't understand why ..." is a polite way of saying "I have some experience on the matter and have come up the belief that ...". The actual conclusion may still be wrong, but I hope this helps with your reading of my comment.
Tech industry has been perpetually growing in the last decades. That means juniors are always a large share of the tech population, and as any demographic, some are bound to be clueless and still vocal. The issue is that in more stable industries, there would be a larger share of seniors to respond with more grounded takes. In ours, these voices are drowned, especially on relatively anonymous media such as HN.
On the other side people were already asking why Twitter didn't do more moderation and better filtering (= more people).
And we expected that breaking rules would have serious repercussions, which was a foolish assumption as we've seen.