I agree about FB. There are things about it that are annoying and just not right. As for HS friends I'm sure there are a lot of people that feel that way. In my own case I was able to connect with people that i actually wondered about. Our 40th reunion was organized there. It has it's value for some people.
Ravelry is a whole different thing. Yes, there are lots of groups, but you don't have to be involved. I've found them useful on occasion for a designer info, special deals found nowhere else, or specific likes or needs. Like there's actually a group for Catholic Nuns! How cool! No, I'm not a nun or catholic, but think its neat.
What I use it for 99% of the time...to look up patterns for myself and to answer KH questions, to look up yarns and see what others say about it (whether its soft, splitty, pills like crazy, is finer than stated, etc.) and what others knitted with it and how it looks knitted up.