First, most psychiatrists do little or no therapy. Second, any psychiatrist worth his salt can have a thriving practice in short order regardless of how many antidepressants are written by primary care physicians. You want to be the big cynic, you're going to need to know a little more about the real world and entertain a few less half-formed theories. Since I have been the Medical Director of a 55 doctor group for over 6 years, I think I can speak with authority on the subject. What makes you so erudite on this topic?
Just a thought: Having something meaningful to do can lift depression. Would participating in a study to help develop drugs to treat depression be a meaningful thing to do?