I'm of the opinion that you shouldn't even be at university if you're not foaming at the mouth to acquire the knowledge.
In principle, I agree. In practice, when a college degree is a de facto requirement for a decent job, you're going to have lots of people there for reasons other than the purity of learning.
And even those who are in there primarily because they want to learn will be very aware that getting a good grade in the exam will most likely improve their job prospects on graduating.
Learning to ace an exam in the minimum time possible frees up the rest of your time to do some actually useful learning.
In principle, I agree. In practice, when a college degree is a de facto requirement for a decent job, you're going to have lots of people there for reasons other than the purity of learning.