I have explained this several times I believe.
The view of the game is from the gun, not the characters eyes. The players do not run around the game all the time with the gun up to their eyes, they have the gun down to their side, around their stomach as they run around. The gun is not planted to the middle of the forehead of a midget running around.
Look at how characters run around, they hold the gun down by their side.
If they actually had the view of the game from the characters eyes, to make the character look 6 feet tall, then your view would be above the gun, making it nearly impossible to aim from the hip because of the perspective of looking over the top of your gun and trying to get a crosshair on someone.
Now when you look down the scope by holding L1 to aim, the characters head goes down some and the gun comes up, meeting each other halfway. This should make the character look/feel a little taller, but it doesn't. HOWEVER, if they did it this way, you could not be able to line something up from the hip, then hold L1 to aim and shoot, since the gun would actually move up and off your target as it goes to your eye.
It is a videogame. Imagine your character has a camera in the middle of his chest/stomach, that is the view you have. That is the view you have so you can easily aim from the hip.
If you did feel like you were 6 feet tall, then people would say, "OMG, are these guys running around with the gun sticking to their forhead??"" or "DUDE, this is so unrealistic, it is like my guy is running around with the gun up to his face the whole time, my gun is like 6 feet off the ground.
Go grab an assault rifle, run around with it as if you are running for your life, but still ready to kill something that may jump out at you, you would not run around with the gun up by your head,
you would run around like THIS, ready to shoot.
Now, look at ARRRRRnold. I know this is an awful example. But this is kinda how you run in KZ2. The camera angle is from the middle of your chest so you can easily aim the weapon you are holding at your side, like ARRRRRnold. Notice how ARRRRnold's gun is probably 3-4 feet from the ground when he walks around, that is the same perspective in Killzone 2. Some look at it as being a dwarf, I look at it as a videogame trying to be a little more realistic.
Other games have done it better, but if you would really think of the Perspective in other FPS, it is like the gun is 6 feet off the ground. Who would really run around with their gun up by their face or above their head? In a real war, y
ou would not run around like this all the time if you were trying to be fast, but also protect yourself. This is how they would run around in Killzone 2, if you think about it, if you wanted to "feel" 6 feet tall.