Why? Programmers should be legally liable for what they program.
Too many degrees of separation between a programmer and the final product and how it's used, usually.
Additionally, the decision to deploy an incomplete product or one that contains known flaws is an administrative decision, not a programming one.
I read somewhere that this claim owes a little too much to the inclusion of pathological cases at the lower end of the spectrum, meaning that since below a certain score like 85 you are basically intellectually disabled (or even literally brain dead, or just dead) and academic achievement becomes nonexistent, the correlation is far more pronounced than if we were comparing educational attainment at the more functional ranges.
Will post source if I find it.