Well, I think there is a semantic difference between saying that they "don't appear to want it very badly" and stating that they "should appear to want it very

Well, I think there is a semantic difference between saying that they "don't appear to want it very badly" and stating that they "should appear to want it very badly". If someone seems diffident, you might say they don't want the job very badly, right? But you wouldn't say that about someone who seemed excited about it. It's just an idiom. You have to show some interest, but you don't have to be desperate. About the "dying for the job" comment, though, I agree that is going too far. Personally, I think you should project a positive attitude about both your previous job, and about the possibility of working at the new place. But never act in a way that implies you aren't on equal footing with the interviewer. It should be a discussion, not a petition.