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 
This. I’m ok with older games without ironsights, doesn’t distract me, but a modern one? Just put that damn thing on your game fuck dammit.
It would be an utterly different game. It wouldn’t be counter-strike at all.