The issue of testing is one fraught with affect. Each is a justifiable perspective, but there is no totalizing answer. One of the dilemmas here is that the academy for so long has sought some universal truth about learning. There is none. We learn throughout our lives, in the most unexpected ways, and we coordinate our learning to produce the most unexpected lifeworlds.
Exams are a very special form of testing, used generally to certify competence.
It means that when we give an exam, we are attempting to certify, to verify a person's knowledge within a given field. So, if sociologists in the real world should be able to discuss intelligently the theories of Durkheim, Marx, and Weber, an exam would ask the candidates to discuss a selection of the theories of Durkheim, Marx, and Weber. You spoke of teachers becoming immune to giving out grades to students, which makes them structurally violent. I agree with your report. I can tell from my experience that some teachers do not want to give or disappoint students with bad reports on their performance.