Human communications depend largely on context. We weren't made to blurt out every one of our feelings and observations to the community at large. Instead, we share this piece of information with this person, ask this other person for advice, listen in on these other folks when they talk about X, etc.
The is the natural way of being human -- to use a phrase from the movie, it's the social experience.
Every technical solution I've seen so far fails to include this contextual nature of communication. It's too much of a pain for folks to pick certain people for certain kinds of talk, and it's all so much a pain in the ass (compared with the old way of physically moving from one group to another)
Oddly enough, this was first noticed with TV back in the 1950s. Up until then, conversations were small and cliquish -- the natural order. TV brought in the idea of "universal" communicating in a way that radio, plays, or newspapers didn't. Suddenly everybody in the family was in the room when Lucy got pregnant, or when Opie killed the bird with the slingshot.
Of course, nobody bothered much complaining back then, because, after all, back in the 1950s what kind of radical information was going to be on TV? And nobody complained (much) when TV got into a lot more controversial issues in the last couple of decades.
But now it's not TV -- it's us. It's our lives, our pregnancies, our sorrows, etc.
I think people need the contextual nature of communication -- it makes society function. But I don't see any technology solution on the horizon that easily and naturally facilitates this. And yes, if it happens it might just be the next FB killer. But that's a big "if". Lots of folks have went down the road of trying to add context, including FB itself, and so far nobody has been successful.