In terms of gameplay mechanics, old school zoom aiming achieves the same thing as ADS. Is getting to press your nose against virtual firearms really that important in a game about shooting werevolves and vampires?
I blame this on the proliferation of Call of Duty over traditional scifi and fantasy shooter franchises. You can fucking ADS on an assault rifle in Halo now 
I have to assume it's got something to do with the cosmetics that were supposed to the main avenue for monetisation in that game. Making separate Elite cosmetic items that only a fraction of the playerbase would use probably didn't make sense
myself and many others i know personally would totally have shelled out for some dope elite armor, i wonder if its a smaller part of the player base than i assume or if its also the devs trying to have balanced hitboxes at the expense of cool aliens