Big mainstream sites like that have never reviewed turn based strategy (heck PC in general..) games very well. For one, they allocate X time per game to their staff, whether it's Halo Reach, or Civ 5.
Now, I don't want to come off as slamming Halo, though I might not be an avid player, I have had fun playing Halo games, and other FPS titles, but it doesn't take as long to really see what they're about, and how good they are, as it does to really see a turn based game like Civ. If the reviewer isn't a fan of the genre, they aren't going to "get it" and obviously underscore the game.
For this reason, places like metacritic, and what I value even more - fansites like CFC and Apolyton, are much better places to get an accurate review of a game like Civ.