So you wanted to delete your account, and you did, but it's presumptuous to assume that Facebook is nothing more than banal games from people you barely know.
Being able to see who is attending what events is a really great feature –I often go to events that I wouldn't have known about if not for Facebook. Even more major events like birthdays where I might get a text message about it, having the event sit there in my Facebook until I RSVP is awesome.
Facebook Groups are excellent because if you're involved in some kind of organisation (dance school, protest marches etc), using a Facebook Group means you can help out with co-ordination, have somewhere to link relevant videos and so.
Sure, I don't care about most status updates, but I really enjoy seeing the photos of friends currently overseas and so on. At least for me, Facebook is actually a really useful social tool.