Facebook is worried that people are reposting fun things and links to other websites instead of sharing their news and views. To share personal information people seem to be preferring private messaging tools such as Instagram, Whatsapp and Snapchat, apparently because people have friended so many, that they don't know which of them might be offended by a post.
Facebook is also far more accessible to potential employers. People have taken to Facebook to report news and opinions, but are less likely to reveal their own day to day activity for fear that any misstep on the social network could cause employment issues for them in the future. It is a world where any piece of information you post can alter people's perception of your character, something that people are simply less keen to do. From Latin Post (my bold).
There are no doubt other reasons, but that's a good start. This is why I preferred Google Plus and it's circles, tho I'm not sure that they are still called Circles. This screen shot is from when I was using G+.
Last night I went to the worst concert I've ever heard from Brno Filharmonie and I could tell you in great detail about the structure of the program, the cadenzas in the concertos, the over-inflated aggression in Schoenberg's Chamber Symphony and lots more. In Google Plus, I'd've happily done so and sent it to my Klassy Musick circle - technically very easy. When I had things to share about Brno, I wouldn't bother my G+ Friends in the rest of the world.
But Facebook is where it was all happening. Thus I returned to a Facebook much changed since I'd left some years before when I was offended by some photos posted without my permission, and someone posting ads on my account. I'm back, as you can see but my postings are somewhat curtailed by consideration for "Friends", who need not be interested in the fat lips of last night's clarinetist's embouchure.
I'd say to Facebook, make it much easier to control who receives our postings. Apparently, it's possible but I'm not aware of anyone doing it.