Let me tell you about my territory's system of assigning tertiary entrance marks.
If you want to get into uni in Australia, you need to get what is called an ATAR, which is essentially what percentile of students in your state your grades beat. My territory's ATARs are based on a set on a certain number of your grades in your best subjects (i.e. I did two math classes a semester, so my math courses counted twice) as modulated for 'difficulty.'
So, how does this work? Well, at the end of each semester you get two grades, one being the letter grade and the other being a score out of 100. However, the idea is that they don't want a single group of people getting shafted based on the fact their teachers were awful (because teachers in Australia tend to be underpaid, overworked, and generally hate it so nobody wants to do it other than people who hate it but can't get another job) so the idea is that your scores are modulated based on the scores of the other people in the course on a set of standardised exams.
So not only is your grade dependant on your work, its also partially dependent on the results of your cohort in these standardised examinations.
Now, if you are smart, what you (and p. much everybody else who's smart) do is take class which smart people who care tend to take (eg. two lines of the hardest level maths class, economics, physics, human bio (for all the med student hopefuls) and there were a few extracurricular courses that you could take at the uni while at school which contributed to your ATAR which a fair few people took, myself included) and, even though you are getting like Cs, your grade is shooting up because of a) internal modulation from taking the highest math course, because they don't want a case where you are incentivised to do lower level courses and get As - I was getting Cs in higher level math and was getting a better actual score my friend who topped the level below it and more importantly b) everybody who does these courses cares enough and is smart and likely middle class enough to do well on the standardised testing.
All this contributes to people who are smart but lazy as hell doing the bare minimum for a "good student", getting ATARs in the top 6th percentile, going to universities for courses with really high ATAR requirements and then promptly flunking out of them because they have no clue how to actually do any work, which is what happened to me and a whole bunch of friends of mine.
Its a system that rewards gaming it rather than doing subjects that you actually want to do.
At least it means that arts electives are the cesspool of stoned hipsters that they ought to be.