Oh, it's a systemic issue, for the most part. And it's not so much actual
spam as it is social spam. Facebook revolves heavily around pushing information towards your attention, and I'm very much a pull-oriented person with rare exceptions.
As to my CSS {display:none;}, though, I ended up distributing it to a large portion of my friends. The overall consensus was (and likely is, though this is mostly before the ability to categorize things) that the feed is:
A) too addicting, because it pulls you back in when you could be doing something else. There's always something interesting going on when you have a lot of connections, and you can't remove connections or risk offending people (though that's largely fixed now). Its mere presence is a threat to being productive, which ends up leaving you feeling like you wasted your day.
and B) utterly crammed with irrelevant information (app this, lame-quote-status-update that, drinking-photos those), so the bits you actually wish to keep up on get lost in the sea or pushed off the end of the world (page 2). I recognize this is a largely un-solvable problem, as everyone is different, but the tool-set simply isn't there to even manage it efficiently.
So it ends up being the zeitgeist of things you're not involved in and you either want to be in on or you want to just shut up. With the occasional relevant flotsam that keeps you checking it through all the failing times.
Last I saw, things had improved somewhat, with the most important step being lists of friends. But I've been out of it for a couple years now, so some of the gripes may not be overly relevant.