I don't think there's anything you can do unless you or a group of like minded individuals own majority share in Facebook. If we pretend you did then all you'll need to do is slowly transform Facebook from the cluster**** it is now into something that's actually useful. If you boil out all of the garbage you'd get something like your typical internet forum where subforums are defined by associations with posters. (I say "something like" pretty loosely here, what I'm trying to get at here is really nothing like that at all from a technical pov)
But more realistically I've got a bad feeling that everything on the internet is going to ****, and I'm not sure if I just haven't noticed it before or it's going to **** faster now. Facebook is a cesspit of advertisements, bull**** games, and people spewing nonsense. Youtube is turning into television, more popular videos are becoming unwatchable unless you want an incredible amount of commercials. You know what, I think the internet isn't much different as it's always been, I'm just getting more and more annoyed by advertisements and people making painfully ignorant remarks.

EDIT: And having a place to say stupid things and be an ignorant **** isn't all that bad either, now that I think about it. Some people use Facebook, some people use IRC, etc. Can't really expect people to be 5 srs take-30-minutes-to-compose-a-response all the time, especially on the internet.