How Facebook Ruined Comments (at Least for Me) | TIME.com

Perhaps Facebook is shifting to comments minus context in order to more directly compete with Twitter...

"Facebook says it’s doing this so that “the most active and engaging conversations among your readers will be surfaced at the top of your posts ensuring that people who visit your Page will see the best conversations.”
The problem is that all the comments on an item — whether or not they’re threaded — add up to a conversation. That’s particularly true now, since Replies are new, not active on all areas of Facebook and aren’t supported by Facebook’s mobile versions. That means that many people — the vast majority, at least on my page — leave a top-level comment even if they’re responding to another comment. Which means that Facebook can’t shuffle the order without destroying context."

How Facebook Ruined Comments (at Least for Me) | TIME.com