It's such a stupid design decision, and it takes away from the graphics, and it makes EVERY GAME LOOK LIKE THE ONE BEFORE.
You'd think that'd be the first thing they change.
It's because it's still the ol' gun on a stick model... until they truly implement first person body (and allow you to look around independent of your weapon, as you can in Arma) we're stuck with this.
To do it right requires a few different stances. There
are times when your weapon
is readied, the position between relaxed and ironsights, that probably would look somewhat like what's seen in the average FPS. And if you're only going to implement one stance in your game, that's the one you use, and that's the one we most often see.
A dev has to care enough to make it realistic, and add different stances (or fake it)... but CoD and most shooters are arcade-like twitch stuff, and I don't think Infinity Ward is gonna blaze that trail, sorry.
Getting mad they don't is a little silly, since it's an unrealistic expectation of this particular developer.