I understand as of the second beta weekend, jumping was already nerfed. However, it is still too effective to jump into a room or around cover and attack someone. When you jump at someone in close quarters like this, you quickly exit their field of view. If you change your controller settings so that L1 is jump, you dont even have to take you finger off of the sticks. This allows you to jump and aim at the same time. This gives you an unfair edge because you are exiting the opponents screen while quickly aiming down and shooting them.
In my opinion, jumping should only be for maneuvering over obstacles. You should doing your gun over back while jumping, making the weapon inactive.
I'm just curious: Are you new to Call of Duty? I ask because jump-shotting has always been a thing, as well as drop shotting. I jump all over the place, and it doesn't seem to help me any.