I have been on HN for nearly a decade now. I don't know if it is a recent phenomenon.
But in contrast to reddit, HN comment threads always seem to go on a complete tangent to the original post.
This renders comments pretty useless for me to find out any insight into the original post. In contrast, you can learn a lot about original post on Reddit via comments.
The pattern usually follows; Commentary on the brand/topic in general rather than the specific news, Personal anecdotes which barely have any connection or insight to the topic at hand, Just a dump of personal preference based on emotion without much insight.
What's going on here? Please go and check any thread.