I was talking to a part-time college professor recently who was lamenting the fact that his students only cared about grades.  Since I'm a bit younger than him and therefore less removed from school, he asked me if I knew why this was the case.  I didn't have a very good answer for him at the time (I can't think on the spot), but after thinking about it some more, I came up with something. 

Students are obsessed with getting good grades because everything in life depends on getting good grades.  Good grades gain you praise from your teachers and parents.  Good grades get you accepted into college.  Good grades get you free money in the form of scholarships.  Good grades save you money on car insurance.  Good grades get you job interviews.  I know from more than one employer that the first thing they look at when gauging a potential future employee is Grade Point Average.  It would be cool if GPA measured something other than test scores, such as how quickly you learn or how good you are at applying knowledge, but unfortunately that's not the case.  Good grades won't necessarily get you the job, but without a doubt bad grades will prevent an interview from happening at all. 

So the real answer to why students are obsessed with grades is because that's what they're taught.  Chew on that, teachers. #education