Supply and demand at work I guess; if it's easier to get project managers than developers it becomes obvious which one should be paid more.

Whenever I hear the term "Project Manager", and imagine all of the confusion collectively experienced by anyone who has had to explain that job, I think of Mr Burns from the Simpsons saying "Am I that out of touch? No, it's the KIDS who are wrong".

Let's call it "Project Coordinator" or "Project Advocate" or something.