The revelation that the median grade at Harvard is an A- prompted lots of discussion, especially among Ivy-league educated journalists. Some speculated high grades reflect intelligence. Others say professors just want their students to get jobs, or, selfishly, they want favorable teaching evaluations. As a teaching assistant in the economics department at Columbia, I too inflated student grades, but for none of those reasons.
I just didn’t want to deal with all the complaining.
Of course, I (and every other graduate student and professor I worked with) read everyone’s work carefully and especially rewarded students who demonstrated a solid understanding of the material. But the distribution of grades was very narrow. Great work got an A, pretty good to average got an A-, slightly below average was a B+, not great was a B, very bad was a B-. Anything below was akin to failure and required showing zero effort or even hostility to the class.