Couldn't agree more! I'm an economics Ph.D. dropout who focused primarily on microeconomics and game theory (because like you said, current macro theory [see: DSGE] is completely bogus) and I think your points about finding monopolies is a great one. I left my Ph.D. early because it was a losing game as I wanted to be learning more computer science since it was a necessary skill to obtain in addition to a microeconomic/econometric education to master the "data science"-esk skills I wanted to in order to ensure I properly aligned myself for the future.
Although I haven't made the move to industry yet, I did recently get myself a nice little research gig doing big data work in a lab at one of those universities in Cambridge.