I had a professor in college who believed an A should be reserved for the rare student who really nails a subject. He felt that if he gave a test, and several students got an A on it, it was a bad test. He said that was like having a speedometer on a car that only went to 50. So if you worked really hard in his class and did well, you'd likely get a B. Most students got a C, because that's average.
I actually agreed with him, but the problem was that the rest of academia didn't behave that way, so his classes lowered your GPA.
There amazingly accurate.