Earlier quoted context omitted.
I often wonder the opposite: why do FB users care about seeing the updates of just anyone in their friend list? But I'm thinking along the lines of a more cynical user, as in, I realize FB is a huge timesuck, I've probably friended more people than I consider friends in real life, I should get off the computer more, etc etc., and so I appreciate the way that FB shows me the updates of people who I'm most interested i…
why do FB users care about seeing the updates of just anyone in their friend list? If the things they're saying aren't (regularly) of value, they wouldn't be on my list.
In cases where de-friending a person has no real-life consequences (i.e. they're not a close friend, either in proximity or emotionally), then FB's curation saves you a little of that tedious cleanup. In cases where it is awkward to defriend someone because you have a real-life connection to them, the curation may save you from having to manually silence their updates.
I can only think of one case where I had to manually perform these silencing actions, and it was with a friend who is a good real life friend and who I communicate on FB regularly, but who has decided to make his wall a constant stream of his political beliefs. Otherwise, I'm pretty happy with the convenience that FB's curation performs in auto-ignoring the people that I tend to ignore (but not necessarily dislike).
There's one more important aspect to this. Sometimes, a FB friend who isn't normally in your Top feed will appear because something he/she posted has gotten a lot of activity/likes. This is not so dissimilar to a place like HN, where the well-liked submissions of people I've never met are prominently visible to me. This kind of social aggregation would not happen in a situation where you've decided to shut out all people that you've decided a priori have and will have nothing of interest to you.