Most college programs has very straightforward tests designed to be easy to pass, and students usually try to learn as little as possible by memorizing the material they can memorize instead of internalising anything. This combination means that a large majority of students who graduate will have a horrible understanding of the material studied. And since students have a horrible understanding and try to memorize, if you design tests that aren't straightforward and easy then almost everyone will fail, so you can't do that...

And then these students graduate, think that the paper is proof that they actually learned these things, but if you prod their knowledge then it all just falls down since there is no substance there.