Why is that? Just a personal observation, but I only actually started to understand programming my junior year of college and would find myself to be pretty technically proficient, and I know plenty of terrific developers who started of programming after a career in something completely unrelated (selling phones, painting, vet school).
Yeah it's hard to start learning how to program and become efficient at it, but there is no reason that we can't attack the issue at later stages in the pipeline.