Friends?

Maybe I am a cynic, a pessimist, or maybe just a realist, but it seems like people these days base friendships on the hedonist principal. Has friendship always been based on a mutually beneficial existence, or was it normal at one time to simply spend time with someone because you enjoyed their company, and experienced some ineffable but joyous feeling in their presence? I am not saying that everyone is looking to purely gain something out of their platonic partner, at least not always consciously, but somewhere along the road one or both people in the relationship develop expectations. I heard a friend say the other day that she was going through some hard times because of the people closest to her, and their inability to consider her when making decisions. I simply told her "stop expecting things of others, and your life will quickly become a great deal simpler". Is this wrong? Is it so hard to believe that most people should not be let into our inner circle? It doesn't seem difficult for someone to let you down when you serve little to no purpose in their life. In that case you become an "out of sight out of mind friend". In my opinion if you have to keep yourself constantly relevant then it might not be a relationship worth having. Maybe some of us just don't understand what a friendship is, or it's simply a case of semantics, and our definitions vary. I don't really know what constitutes a "friend", and I'm not even sure if I have any. Maybe my problem isn't so much with the people around me, but more so with the term and its connotation.