Is that reason because things are roughly sorted by time?
It's a timeline of interesting events in the recent history of your friends and interests. Being a "timeline" doesn't mean that it has to include everything. Should a timeline of the history of the USA include every event in the history of China? Not if you actually want to succeed in communicating any subset of the information on the timeline effectively...
People expect to sign in and see stuff about their friends. They don't expect to have to hand manage every single connection they ever make to decide who is or isn't worth paying attention to.
> Twitter works that way and nobody thinks it's broken.
1) Twitter has extremely different use cases.
2) I think Twitter is horribly broken. I rely on non-broken external clients to sort and filter tweets; most high volume users do.
> If someone spams your timeline it's really easy to unfollow and solve the problem.
Again, Twitter is a totally different use case. I might not want to unfriend my Aunt, who loves me very much, but I sure as hell don't want to see her every little post. I don't interact with her messages, so Facebook stops showing them to me. That problem seems solved to me...
