There is a lot of crap on Facebook, no doubt about it. I just visit it once a day for a quick browse. I don't do any of the games or surveys or countless other applications. There are usually funny photos that get posted or silly things people I know like to 'share'. Like: Do we really need a Lysol product scented like Lavender? Wouldn't the scent put you to sleep before you finish the kitchen floor? (silly stuff like that) Also my Facebook friends often share interesting news articles. (I think it's dangerous to complain about work, however...and I am always amazed that some people don't see the danger in THAT. Like the nitwits you mentioned...IT'S PUBLIC INFORMATION!)
I use it to promote my blogs. I write under a pen-name, so recently set up a FB account under that name. I link to my blogs and also share posts etc from others. Is a way to read interesting posts from others too. Most of these people I've never met.
I don't use the one under my real name much. It has a bunch of people from my past like happy clappy christians & people from school I barely remember. I have a note on there if anyone wants to read my blogs about losing my faith in god, then contact me. Only the non-judgemental christians did so.
I was reluctant to join facebook, as thought I wouldn't have friends (I'm not a very social person). There are some friends I lost contact with long ago but most are acquaintances and relatives I hardly know.