Realistically, any component of a game (or the game as a whole) will mostly be judged as being "Poor", "Below Average", "Average", "Above Average", "Good", and "Great" which can easily be judged on a scale out of 5 (0=Poor, 1=Below Average, 2=Average, 3=Above Average, 4=Good, 5=Great).

The only thing a 100 point scale does is encourage mindless arguments over whether a game that got 97.6% is better than a game that got 97.2%; where reality dictates that both these games are probably "Great" and your personal preference matters more to which one you enjoy more than the actual quality of the product.

I like this. I think all review systems should be like Ars Technica's - Buy/Rent/Skip. If you want to know whether it's worth playing, read the verdict. If you want to know how good it is, the text of the review is the best way. Not the margin between an 8.9 and 9.0

Here is an idea instead of changing your scale to .0-.5 why don't you change your review system. Stop being so damn PC and actually write some critical reviews. Here is a novel concept multiple reviewers, which would fix the problem of games like Brutal Legend getting 9.0 when it really deserves a 7.5. Or MGS4 getting a 10 when several of your PS3 editors can't stand the combat system. 

They should remove the review score all together, and just focus on the written review.

?

oops, cut and paste from word

Good.  No one can tell the difference between a 7.6 game and a 7.7 game anyway.