Those stories are barely more than gossip and belong on mainstream news sites. It doesn't look like they were generating much of interest in the comments either, just the usual go-my-team rhetoric and unfocused outrage in a random direction.
Do you think the comments section of other types of HN stories are held to the same standard? Or do you think the promptness with which these stories are flagged has something to do with their subject matter?
If you have a number of people acting in the way you describe, you end up with an echo chamber, which is what the article is noting.