String Theory: gathering critics

In answer to Edge's question "What do you believe is true even though you can't prove it?" Philip Anderson says

Is string theory a futile exercise as physics, as I believe it to be? It is an interesting mathematical specialty and has produced and will produce mathematics useful in other contexts, but it seems no more vital as mathematics than other areas of very abstract or specialized math, and doesn't on that basis justify the incredible amount of effort expended on it.

I'm beginning to hear this more frequently about string theory. For example, Not Even Wrong: The Problem of Predictivity

In recent years, as it has become clear that string theory can never be used to predict anything about the real world, string theorists have reacted to this state of affairs in various often bizarre ways. Tonight there's a new review article by Steve Giddings about string theory which doesn't even pretend that the theory will ever make a real prediction about anything. … [T]he really hilarious thing is the way Giddings motivates string theory. In a section entitled 'The problem of predictivity' he argues that our inability to make quantum gravity predictions at high energy is a problem of supreme importance, then goes on to use this to motivate the introduction of string theory, which in the end gives a theoretical framework unable to predict anything about anything at any energy.