I would call that the pathological case rather than the average one. Maximizing grades against learning as little as possible is the lowest hurdle you can cross while still technically being successful as a student.
It's also worth remembering that "student" does not always mean "child currently undergoing mandatory education". I would think that adults who return to complete their diplomas/degrees or add a graduate-level program on top of the undergraduate one are comparatively more likely to choose to maximize knowledge rather than just grades. It's mostly commonly expressed as "now that I'm personally paying for it, I want to get my money's worth".
It's also worth remembering that "student" does not always mean "child currently undergoing mandatory education". I would think that adults who return to complete their diplomas/degrees or add a graduate-level program on top of the undergraduate one are comparatively more likely to choose to maximize knowledge rather than just grades. It's mostly commonly expressed as "now that I'm personally paying for it, I want to get my money's worth".