The reason you haven't heard it is because nobody wants to say it out loud and get the resulting blowback: it's because college attendance is a proxy for IQ, wh

The reason you haven't heard it is because nobody wants to say it out loud and get the resulting blowback: it's because college attendance is a proxy for IQ, which is far and away the strongest correlating factor with job performance. Since the Supreme Court ruled that employers can't use IQ tests in hiring decisions, they use the presence of a college degree instead.