I really enjoyed this brief article by John Herrman on why comments are a lost cause for publishers:
The online publishing narrative of the last few years, crudely, is this: Social networks are increasingly where people find things to read; people use social networks most often on their phones. It follows, then, that an increasing number—on some sites, a majority—of readers are coming to articlesthrough comments, which command them to click on or tap all manner of internet objects, including but not limited to acts of journalism. Reading news on Facebook is like reading the old internet upside down and inside out; it’s sort of like an infinite scrolling front page composed exclusively of reader comments, which are responsible for leading you, backwards, to the articles they reference. The lunatics run things now—they write the first headlines. They also happen to be your friends.
This means that publishers are not really in a position to solve the problem of comments—it’s the commenters deciding, day in and day out and with no sense of duty or preciousness, what is to be done with news. (It is to be ignored, mostly.) The comments this project refers to, the ones it’s trying to save, are comments in an older sense; words tacked onto the side or bottom of stories written by professionals for very popular websites, written for everybody and nobody at once.