My take on it is that CS degrees aren't that tightly coupled to programming aptitude. Lots of folks get CS degrees and aren't good programmers, so the value of the degree seems questionable. And, let's be honest: for a lot of standard IT jobs, it probably doesn't matter that much. Navigating office politics may in fact be a much bigger predictor of success.

It could well be that the value of a CS degree isn't a linear effect but an interaction: it makes the best programmers better, but doesn't do much to lift the median.