I've used Twitter to poll peers, learn new things, coordinate meetups, find out breaking news, discover useful resources, and more. All of those are valuable to me.
In the end, it's what's valuable to you. If you can't (or don't want to) find a group of people to follow that you find interesting, helpful, or whatever, that's fine. Just because you (or sharpn, or my wife) don't find the service valuable doesn't mean that there's no value in it for anyone, though.