I agree with you, and the GP. Hyper-realistic movies depicting human unpleasantness aren't much different to hyper-realistic games depicting human unpleasantness.
Why do people enjoy spending their leisure time experiencing that? It's not a rhetorical question.
I enjoy movies that make me uncomfortable because of the self-reflection they tend to induce. Those films don't make me want to treat people poorly, they make me want to be kinder.