D'oh! /homer simpson impersonation.

I meant to say that criticism of the [i]subject matter[/i] because it isn't to your taste is not allowed, as I used the BDSM example, above. But, it would be just as invalid to say you don't like the plot because you don't like bittersweet endings. Saying you don't like the plot because the bittersweet ending doesn't follow logicially form the plot as it unfolds is a different kettle of fish.