Subgenres should not be types of Keywords

A year ago I posted this thread. In it, I argued that IMDB should transition to an upvote/downvote system of applying keywords for titles. It was mostly disliked and rejected by commentors there for fear that factual keywords would be voted off of profiles (a possibility, albeit under that system anyone could vote them back up... but the possibility also currently exists now anyway as any random shmuck can remove any keyword without any argument, until someone notices) - but I digress....

Keywords are supposed to be factual, and refer to plot elements. Things that characters are. Where it is set. Specific events that happen. They're also an accepted place for subgenres -  but subgenres themselves are by their nature subjective, yet also very useful and important. I have been going through some of the keywords subgenres on the site myself in some areas, and been adding or removing what I regard as relevant or incorrect subgenres. But when it comes to removing "incorrect" subgenres... how would I necessarily know this all the time? What would make my judgement correct over someone elses? I can spot obvious faults, but there have been many times where it's a bit of a grey issue. Is this psychological horror? Is this black humour enough to be black comedy? These are subjective assessments.

I feel like "subgenres" should be an upvote/downvote component of the site separate from keywords. That way debates over what *type* of show should rarely intrude upon the staff, and the system (unless its obvious vandalism like someone tagging "space opera" on a medieval film). This has worked to great effect on other sites like Rateyourmusic, where the community pools together its shared understanding to apply terms to albums (and films, since RYM has a film component now).