I wonder how much of a persons impression of this is formed by their browsing habits.
As a parent comment mentions big threads can be a bit of a mess but usually only for the first couple of hours. Comments made in the spirit of HN tend to bubble up and off-topic, rude comments and bad jokes tend to percolate down over the course of hours. Also a number of threads that tend to spiral get manually detached which takes time to go clean up.
Someone who isn't somewhat familiar with how HN works that is consistently early to stories that attract a lot of comments is reading an almost entirely different site than someone who just catches up at the end of the day.
some of the more negative threads will get flagged and detached and by the end of the day a casual browse through the comments isn't even going to come across them. eg something about the situation in the middle east is going to attract a lot of attention.
As a parent comment mentions big threads can be a bit of a mess but usually only for the first couple of hours. Comments made in the spirit of HN tend to bubble up and off-topic, rude comments and bad jokes tend to percolate down over the course of hours. Also a number of threads that tend to spiral get manually detached which takes time to go clean up.
Someone who isn't somewhat familiar with how HN works that is consistently early to stories that attract a lot of comments is reading an almost entirely different site than someone who just catches up at the end of the day.