I agree. But I think Twitter is different in the way that it can be a great marketing tool for small businesses and individuals. It's a quick and effective way of letting a lot of people know what you're up to.
However, I don't understand people who chat on Facebook. Especially with people who live in the same town as them. If they're your mates you'll have their phone no, email add. etc. anyways. And, as you also mention, what happened to actually meeting up and having a chat face to face?