@OP: good post. I'd add (but that's really included in artistic choices) that two other things that somehow make GoW2 look worse are a not very natural crossbreed between realistic and artistic environments and excessive machismo in characters' characterization (forgive me for this calembour ), although not to the level that makes me impossible to take Master Chief seriously
But as you showed, characters aren't so good in KZ2 either, in gaming we're still far away from realistic faces and skins, and the best examples fall sadly into the dreaded Uncanny Valley. But this one is a current problem of every platform.