To have a good chance at becoming a viable replacement, all of this functionality would have to be replicated in a single service. Taking on a multi-billion dollar company's cash cow product head-on is quite a difficult task.
I actually do know people who strongly prefer their friends not to have a Facebook account. So this is a feature and not a bug, since it is a strong opportunity to sort out to whom of the Facebook "friends" one really wants to stay in contact with.
Or to give another argument why this is a feature and not a bug: About everybody who has used Facebook for a long time also has collected "friends" that one would love to drop from the friends list, but has not done for politeness. This is finally an opportunity to get rid of them in a much more socially accepted way.
My impression is that this strongly depends on the social circle the respective person is.
You first have to keep in mind that in Germany many people indeed use Facebook, but it is not not that deeply integrated into the life as it is my impression that it is the case in the US. Also in Germany it is often the case (at least in my impression) that people that come to some gathering explicitly say that don't desire that anybody puts some photors that were made of them on Facebebook.
In this case: if I were living in the USA, I probably were in a tiny minority. I am also probably a minority in Germany, too, but it is not my impression that this minority is tiny.
Can confirm, coming from festivals I'm not allowed to upload some pictures to FB and have to send them via email to a bunch of different people who'd still like them.