The problem as i see it is that the OP thinks Iron-sights try to make games realistic.
They don't. They try to make games "Immersive". It feels good when you aim down and shoot a stupid hip-firer in the head. It adds to the tactile feel of it and, in most cases, works great. A similar system of immersion, is the little diagonal cross that appears when you hit people in most modern FPS Multi. Think about how much LESS fun you have when killing AI in SP because that diagonal cross does not show.
They don't. They try to make games "Immersive". It feels good when you aim down and shoot a stupid hip-firer in the head. It adds to the tactile feel of it and, in most cases, works great. A similar system of immersion, is the little diagonal cross that appears when you hit people in most modern FPS Multi. Think about how much LESS fun you have when killing AI in SP because that diagonal cross does not show.