WARNING: CEREAL BUSINESS
The ten point scale is intrinsically flawed. Not only because Killzone 2 got a 7 from Edge (THOSE MICROSHITTING FAGTARTS SHOULD BE HUNTED DOWN AND KILLED! -CTZ), but because the 5/10 isn't average. If it were average, the scores of every game of a console generation should be added up, and then divided by the total number of games. That is an average. Besides, even on a scale of 1-10, the average is not 5. It's actually 5.5.
This isn't the only problem with the ten point scale. There is no such thing as an objective choice of score. Everyone is biased in some way (and Jim Sterling is biased in every way possible, and then some). This renders reviews COMPLETELY unreliable. On the internet, no one can be trusted not to lie except Fox News and 4chan's /b/ board.
As I said, the ten point scale is a creation of the devil, and should never be used under any circumstances.