@numbers: I think a lot of reviewers do take these things into account. However, not in the way you might expect. It is very safe and easy to produce media with soundtracks, art and story that seem "decent" simply by sticking to a general "trend".
The issue is, all the media that follows this safe principle, will end up looking and feeling very similar, and thus it becomes impossible to actually distinguish them based on these criteria, unless it obviously fails. When you read a review with a good score, and art or soundtracks aren't discussed much, that just means that this game doesn't "offend" this taste.
On the other hand, if you really care for innovation or exceptional quality, most reviews won't help you much. There's simply no place on a numeric scale, for a game that many people might find exceptionally good. Why? Because in those cases, there's usually at least as many people who have a different taste, and who will hate it for the same reasons those other guys loved it.
The story is similar. I'm active in game-development on a small freeware game, and personally I'm someone who cares a ton about consistency and good story-telling. On the other hand, if I bring those points up to the community of that game, I will be shunned. Yes, they will absolutely hate me for it, because they don't nearly have the same requirements towards consistency that I do, and they will view any discussion of it as a waste of time.
Does that mean I'm right and they're all stupid? No. Does that mean I'm being silly because I don't agree with the masses? Hardly. It just means that there are different tastes, and sometimes to make a small group of people with unusual taste happy, you have to make your game absolutely awful for everyone else.
Neither are there many game developers who would take this burden on themselves, nor are there many reviewers who aim to make money by appeasing niche communities.