If you've ever attended a German public university you would realize that they strongly operate on Darwinist principles with every incentive to kick students out with hard exams because the students aren't a direct source of funding.

During my bachelor degree the average exam had a 30% failure rate and the first semester exams almost 55%. If you fail an exam three times in a row, you're not even allowed to shop around universities, because you're banned from studying that degree for life. Instead, you're forced to find a similar degree that doesn't have course overlap on the exams you failed, which means you can only transfer some of your credits to the new degree. It's do or die.