True, Review Scores in and of themselves aren't bad. But there is a fundamental problem with rating a piece of entertainment like a consumer product. While a consumer product is usually meant to be replaced, entertainment is different. If you rated a movie when it came out in theaters, should you give it a second score when it released on Blu-Ray? No, because the quality of the piece doesn't change, just its value. Quality and value aren't the same thing, and the industry at large really needs to acknowledge that, IMO.
If the industry wants scores to mean something, they need to change two things.
First, the length of a game shouldn't affect the review score by itself. Sure, $60 for a 5-hour game probably isn't worth it, but that has nothing to do with the quality of the game. If something like Portal, for instance, were released as a stand-alone $60 game, should it be considered a lesser game than if it was sold for $10? Letting price factor into a review of entertainment also damages the score by dating it; in a year, a game can drop to half its price. Should it be considered a better game if it does? If people really want to address price, they should do it, but not as part of a score. Set a price limit, or a recommended format, but don't consider it in your score unless the length, or lack thereof, affects the quality of the game itself, not its value.
And second, the review scales should not use other games as their base. This might sound stupid, so let me give an example. New Super Mario Bros released more than 3 years ago, and got scores in the high 80's. New Super Mario Bros 2 released this year, with scores in the high 70's. Most (but not all) reviews I've seen credit the lower score to the game being too much like its predecessor. What does that have to do with the game's quality? Nothing. It has everything to do with the game's value. I see the same thing when games are compared to one another. A game's quality shouldn't be dependent on what its competitors are doing, but on its own merits. This also dates the review further, because its dependent on games that were out at the time of the review. Its value should be what's affected, not its quality.
Now I'm not saying that other games shouldn't affect scores at all; in fact, by defining a critic's quality spectrum, they already are. But the level of engagement should be what's scored, not how much the game is worth. If they want to include that, they should score the game's value separately.