Simpsons paradox. People without qualifications have to be obviously competent to be hired to do a job. If someone is clueless they probably slipped in because they got certified somehow (like with a degree).
Expect a negative correlation between certification and competence (in the workplace) because the workplace only reliably excludes people who are incompetent and unqualified. So the population sampled is made up of [qualified, competent], [unqualified, competent] and [qualified, incompetent]. And anyone who isn't ready for that will get very confused when they try to work out how much value a degree adds in their pool of programmers. Or any department, really.
Expect a negative correlation between certification and competence (in the workplace) because the workplace only reliably excludes people who are incompetent and unqualified. So the population sampled is made up of [qualified, competent], [unqualified, competent] and [qualified, incompetent]. And anyone who isn't ready for that will get very confused when they try to work out how much value a degree adds in their pool of programmers. Or any department, really.