[quote="AlmostDecent"]How can you say that a grade given by an editorial staff is significant, but that the average grade of THREE editorial staff members is not?[/quote]
Long answer:
http://www.edge.org/3rd_culture/lanier06/lanier06_index.html
My answer:
I said "It's one thing thing to be nominated by editorial staff, it's another thing to be nominated by a statistical flux." Nomination for game of the year is (when it's done by people) a symbolic/conceptual gesture. It's different from grading game in terms of digits. Digital grades are meaningless no matter how many of them you take.
But I'll try to answer you question's substance. Let's say one guy says that Pathologic is a good game. Probably, you can then deduce what kind of game it is by looking at statement and personality and background of that person.
Let's say you take 2 more people. One says that a game is horrible, another says the game is average. This is not, really, a digital scale, but for the sake of argument we convert it to one.
Bad = 1, Average = 2, Good = 3.
(1 + 2 + 3) / 3 = 2.
So, according to our crude aggregation the game is now Average, but the dominant majority of our sample doesn't agree with this. By averaging three grades into one we just lost some very important information.
This is a simple example, but it only gets worse in real life. The scales are meaningless from the beginning. One journalist thinks that 7 is a good game, another thinks that 9 is a good game, while 7 is a mediocre piece of crap. So 2 journalistscan agree that the game is good, they can agree about the extent to which it's good, but assign different grades on 1-10 scale!
Then we get the reader to do the same thing in reverse. One thinks that 7 is average, another thinks that it's good. Which one is true?
But wait, we skipped a couple of steps! The system must first select which websites to use for averaging and which formula to use to calculate the average. It can be mean, it can be median, it can be rating formula for figure skating (which discards the best and the worst grades), it can be _anything_.
Etcetera.
This is, of course, a description of grading woes. There is also a simple (and very unpopular) truth which precedes that argument: a game cannot be summarized by a single digit, period.