I don't know the first thing about statistics, but I know that the set of people reading this website are in a selection problem- everyone here could probably learn to program and go some spec work. For each person here, there are some ratio of other people that cannot do this work. Why they cannot is undefined. Maybe it's as simple as they find it boring or have a low dedication. But I believe it is a fact that there are some number of people who cannot simply ramp up their mental aperture and get a better profession.