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 
Yeah I think sights work best in games where you're engaging targets at a longer range, say like ARMA, where you can also adjust them to based on range (I think or maybe a mod did that). Corridor shooters or games with a focus on CQB feel snappier when it's firing from the hip.
If they want iron sight realism they need to go all the way and make diopter sights actually usable, i.e. the ring goes out of focus and you get a nice aperture on the front post, instead of how it usually works which is a giant black disc blocks 90% of your screen and you get a tiny dot in the middle to aim through.
Same with notch and post sights, no, it's not just a black rectangle that blocks half your field of view.