I suspect we're in a bubble. Consider the charts at the end of https://users.ssc.wisc.edu/~hauser/merit_01_081502_complete...., specifically the "Computer occs." results. I don't think most people are smart enough to become professional programmers if they have to compete with existing professional programmers for jobs. I do think that if you look around the average office which employs programmers, most of the people in non-technical roles could have become a professional programmer, but that's a biased sample.