This is one thing I think Google+ got right. I can have different types of “friends”, each in their own categories, such as “sharaholic” or “meme poster” and only visit those circles occasionally.
The only problem is the unpopularity of G+.
The only problem is the unpopularity of G+.
But people don’t fit neatly into those categories. You’ll miss an important life event from “meme boy” or “share girl” if you’ve filed them neatly away like that. G+ is unpopular because their solution to organising your friends is worse than the competition.
Sure, but how would you classify Meme Boy in circles so that you don't see his memes but you do see his important life events? Or Share Girl so you don't see what she had for lunch but do see important things?
For Meme Boy, a baseball bat to the kneecaps works best.
But really, if Meme Boy enjoys posting memes, he likely already will have a Meme Circle. So you just ask him to remove you from the Meme Circle.
If you look at facebook's primary purpose as a contacts manager and the secondary purpose as a "keep up with other peoples lives feed", then the primary purpose is still served even if you choose not to see everything everyone shares.
For example, I have a list of friends who are into hiking that live nearby. I also have a list of friends that are into hiking who live all over the world and another list of those who just live nearby.
What I want to do is add a friend to the list of friends who are into hiking that live nearby and have them automatically added to the other two lists.
On the other hand, some learning algorithm which figures out what is relevant to you sounds interesting at first but could, in my opninion, quickly lead to creating a bubble in which you only see what some algorithm considers relevant and nothing else. Now I get that some people like it that way, and in the end we all live in some kind of bubble, but still, I'd rather keep options open and actively look for new things I know nothing about.