I don't think he's suggesting they're overpaid. He's just wondering how much he's contributing to the world, despite his high pay and societal praise. If anything, I think it points out the fallacy of thinking that our pay and our personal interpretation of our "worth" are in actuality totally disconnected, although we may feel differently. He feels, I would imagine, some angst over the fact that his contribution to the world may not be worthy of the money he receives. It's an interesting point, and a tough one to wrestle with. Lots going on there.