I will tell you from first hand experience that if the kid in class has a goal that falls short of "Attaining a lasting grasp of knowledge and a spark to pursue their passion," that kid is being set up for failure.
I have never been an "A" student in college, but no one would argue that I was one of the damned brightest kids that my highschool spat out. (Given the school had a very large population of underachievers, this undermines my previous statement a little bit.)
When a kid focuses on good grades to attain some immediate reward, they have NO incentive to actually learn anything. They want to pass, to get points, to make the grade, for relatively short-term gratification. Incentivising learning in grade school or college to pay out for good grades would not help kids actually do better. It would only cause kids to scramble quickly to get the reward and do whatever it takes.
Also, on a similar note, attend college, work full time to afford college, allow grades to decline to work for minimum wage to pay for college. Almost the same scenario. Sacrifice the end goal of overall success for a small intermediary (and trivial) goal.
Just my two bits... I am very opinionated on the standard education systems used globally.