Grading creative writing is always an ethical dilemma. But what you brought up about grading personal stories versus the research paper is of course a truly volatile issue in teaching memoir or the personal essay, because there's no pretense that the narrator is a character.
The people no longer seek consolation in art. But the refined people, the rich, the idlers seek the new, the extraordinary, the extravagant, the scandalous. I have contented these people with all the many bizarre things that come into my head. And the less they understand, the more they admire it. By amusing myself with all these games, all this nonsense, all these picture puzzles, I became famous. . . I am only a public entertainer who has understood his time.