If they are consistently wrong within a given margin of error, then they are still very useful. I agree that we'd need to define our terms here to have a meaningful debate.
I mean, they're not useful at all, let alone "very useful". Can you explain what the use of this article is assuming the classification of movies in various categories (e.g. future, present, past; world better, same, worse) is consistently wrong? To me it seems clear we can throw it all away, as it is now just a bunch of meaningless words.