It's a combination between the Spolskyesque "The hiring pool will always be sucky because it is, definitionally, always going to be heavily weighted with people who have not yet succeeded in getting a job" explanation and "At many firms, actually being able to program your way out of a paper bag is not a prerequisite for being hired as a programmer."

At my old day job, probably half of our system engineers could not program. They generally spent their time producing documentation, gathering requirements, writing emails about requirements that needed more documentation, and occasionally breaking out Eclipse to spend 6 hours trying to add an if statement to one web page by patterning it off of parallel structure in the file they could copy/paste and then random walking through the space of all possible tokens until they found one where the output matched expectations.