Right, a college degree unfortunately at times is basically a proxy for an intelligence test, a way to filter out job applicants. It is a signifier - this person did well enough in school to get into and through college. I'm not judging it in itself as bad or good. It does explain why, however, colleges can get away with poor teaching and little learning on the part of students sometimes (see the book Academically Adrift), and why there is of course a huge bias toward hiring students from more prestigious (selective) colleges.