There are going to be people who, if they give the game a reasonable try (not just the demo), are going to think it's a suckful game. It stands to reason that some reviewers are going to fall into this category.
If you want to see wide variance in entertainment reviews try Rotten Tomatoes for movie reviews. There are very few movies that ever get a 100% fresh rating, whereas if the same pass/fail criteria was applied to games there would be so many with a 100% pass mark, even if you set the bar at 7/10 for a pass (RT sets the pass mark at 6/10 for movies). In reality there is a great deal more uniformity in game reviews than other entertainment reviews. What that uniformity leads to is far too much emphasis on outlier individual scoress and overplaying the negligible differences in metascore (96 metascore means a game "wins" over a 95 metascore, ridiculous)
Heavy Rain in a rotten tomatoes system would be sitting at 97% (66/68 positive reviews BigPond Game Arena just gave it 4.5/10).
UC2, ME2, MW2 and Bioshock 2 would all be at 100%.
AC II (which has a higher meta score than Bioshock 2 and Heavy Rain) would be at 96% (3 low reviews out of 80).
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix