Well that's hardly a high standard. If you're at all good at what you do you setup contracts. Anyone who tries not to pay you, gets hit with a lawsuit and will pay out immediately. Never had that problem, or heard of good studios having that problem.

I think the first guy (talking about the doctor analogy) and the guy who said good clients are ambitious, nailed it. Clients that just want to put out another iteration of the same common shit are useless. If I had to go into work everyday and work on projects like that I'd shoot myself. But when there is respect between the client and the designer, and understanding of creating something unique and ambitious, something world-changing, or at least field-changing, then being a designer is the best job in the world, and the client will have the best possible product.