Facebook doesn't really have a targeted audience anymore. It's pretty much everybody. At this point its like deciding not to use the telephone because the line could be tapped. Facebook is becoming an essential communications platform for a lot of people. Particularly people under 20.
Events - a lot of people post events on Facebook and trust that all of their friends will see it.
Photos - a lot of people only share photos through Facebook. If you want to see or download photos someone has taken at an event you were at your probably need to use Facebook.
Email - most younger people do not use email (unless they have to for school/business. Instead they use Facebook messages.
I won't bother addressing you last comment. Maybe your experience of high-scool was different than mine was, which consisted of a lot more that 'silly high-school gossip'.
Really though, you're choosing to socially isolate yourself in two ways. First from everyone using Facebook for social organization (the status stream is considered as almost a joke by now by a large portion if users).
But you're also isolating yourself by simply drawing a point that you don't have Facebook anymore. It's an eye roll producer on the level of saying "Oh, I don't have cable/TV anymore." Sure, lots of people agree with that notion but it's used to drive a wedge in-between you and others by most
