I wouldn't even worry about how useful the rating systems are, I'd worry about how arbitrary they are even if you accept their standards. E.g. the "one fuck" ru

I wouldn't even worry about how useful the rating systems are, I'd worry about how arbitrary they are even if you accept their standards. E.g. the "one fuck" rule for PG-13 films, except a film like The Martian can say it twice without being rated R because the raters vote on what they think American parents would think about the film in that case.