Look, hip shooting is real, it can be done and has been replicated in game. It may need tweaking though. To move it more towards RL implications. In RL using your sights is your best option, period, 100% of the time. It gives you your best chance to hit what you are aiming at. No military force in the world teaches "hip shooting" as a viable technique. "hip-shooting" is a desperate act usualy reserved for situations where there is no other choice, essentially you got caught with your pants down holding "mein teil" so you spray and pray.
What needs to be tweaked is to make it so that "hipping" is not reliable enough and will not be the 1st option a person goes to. Not much tweaking is neccessary, it is pretty good in game as it is. Spraying with an automatic gun is pretty easy, with so many rounds coming out, it is fairly easy to "walk" your shots onto a target. Not enough fed back is given to us from the game to see the impact of every shot in the environment, but IRL you would see holes every where around the target and compensate your aim accordingly, but we only get a fraction of that info from the game so you just keep moving and shooting. In CQB, it is pretty effective, as it would be IRL. The problem is your 1st shot or the time that you have to take to correct the shots to the target (unless lucky). The ready target using his sights (if he is skillful with his weapon) should have the advantage as his first shots will be good right off the bat, the "hipper", unless very lucky will be at a disadvantage for some seconds while he compensates his aim.
In real life, when your life is on the line for real, you try very hard to eliminate "lady luck" from any equation. You want to make the outcome absolutly in your favor, so you aim down the sights when ever possible to ensure your shots will be as true as possible. Since this is a game and you will just respawn, why not use a technique that involves luck and some guessing.
In the end, if they never changed the way it is now, it is still way better than most games. We just need to come up with ways that will force players to not hip shoot most of the time with out major changes to the current game play. I can't think of any, but that does not mean that someone out ther does not have a good idea, but for now, "hip shooting" is pretty good they way it is.