In the old days (a millenia ago) Universities (teacher's guilds, literally) didn't test students - the Church tested the students and credentialed them, not the teachers. The great advantage of this was that there was no grade inflation or other funny business, 'cause there was no conflict of interest. Now, the academy grades its own work, in effect. Back then, if you could get the study in on your own and pass, great. If not, you found a professor and settled on a fee. Now, the academy is an old boys' club, and can get very inbred, and be a decade behind the market, too. In computer science, if someone's a prof at most Universities, it's often a sign they aren't competent enough to survive in the wild.