So, you mean to say humans in Halo are fascists? And also in Starship Troopers? And that they are being attacked by an invading force is not good enough reason to fight them?... Wow, I think you just blow my mind. There I was, thinking that the name "Spartans" was just a happy coincidence, and a society full of armored living weapons was my idea of utopia... What is next? Starcraft space marines being a bunch of rednecks with big guns?
Seriously, you are reading too much into it. The game is set in a dystropian future, it is not meant to be taken literal... If you want to pick a target on Halo, target it for its lack of evolution, bland level design or something that makes sense in terms of the game, not because you find the fictional setting offensive. That is like parents complaining about GTA because they assume that is the image of the world their kids are hoping to live; or people complaining about 1984 for being a bad "influence".