Personally? I like being able to aim down the sights of whatever weapon I'm using.
Perhaps it doesn't add realism, but it does add one thing that hip fire does not: Control.
If I am aiming down the iron-sights intentionally, it means that I will be having more control over where I'm aiming, and what I'm shooting at. If what you're saying is true, you technically shouldn't be able to aim at hip-fire without having completely wide shots with no accuracy and horrid recoil, save for when you're using a shotgun, where those two things don't matter at all.
Besides, the thing you don't quite get is that when you're using Iron Sights, you're taking the weapon from being at hip position, to being at shoulder position, where it is properly held for firing. It gives you more accuracy, more recoil control, and you can use the sights that were built into the gun instead of guestimating where the reticle is. The closest thing to actual realism I've found in a shooting game is through Killing Floor: there's no reticle at all, and you have didly for accuracy unless you put the gun in iron sights.
In other words, if they want actual realism, they'll have both hip fire and iron sights. Hip fire for spray and pray with no accuracy and horrid recoil, but it works for close range. Iron sights, meanwhile, will be the exact opposite: less reaction time to enemy movements, but more precision and less recoil, since you have the butt of the weapon against your shoulder.
Perhaps it doesn't add realism, but it does add one thing that hip fire does not: Control.
If I am aiming down the iron-sights intentionally, it means that I will be having more control over where I'm aiming, and what I'm shooting at. If what you're saying is true, you technically shouldn't be able to aim at hip-fire without having completely wide shots with no accuracy and horrid recoil, save for when you're using a shotgun, where those two things don't matter at all.
Besides, the thing you don't quite get is that when you're using Iron Sights, you're taking the weapon from being at hip position, to being at shoulder position, where it is properly held for firing. It gives you more accuracy, more recoil control, and you can use the sights that were built into the gun instead of guestimating where the reticle is. The closest thing to actual realism I've found in a shooting game is through Killing Floor: there's no reticle at all, and you have didly for accuracy unless you put the gun in iron sights.
In other words, if they want actual realism, they'll have both hip fire and iron sights. Hip fire for spray and pray with no accuracy and horrid recoil, but it works for close range. Iron sights, meanwhile, will be the exact opposite: less reaction time to enemy movements, but more precision and less recoil, since you have the butt of the weapon against your shoulder.