Chief wears his armor for a reasoning, and I have yet to play this game but from what I know from researching halopedia and rumors spartan IV's hate chief. Chief has emotions for spartans, can't stand losing them either; but if they treat him like crap that'd make him feel like a lone spartan. He where's the armor to show his respect for spartans, his identity doesn't need to be revealed it's just like me getting you a free girlfriends. She has everything you want, but her looks make you not want her anymore. see what I'm getting at?