These days schools in the USA are more focused on passing grades than the actual learning process. I've seen plenty of people struggle in school, fail their class, and drop out or even commit suicide because they're too stressed and feel that there isn't a future for them or that they're too stupid to pass. I've seen my friends struggle so much that they've burst into tears when they've failed.
Failure is seen as the worst thing in the USA schooling system. If you don't pass a test you are punished. You aren't praised for what you know, the points you did get aren't counted positively towards your grade. Failure ruins you in school. It teaches you not to try harder, but that you aren't smart enough to pass or retain knowledge.