I think we should take a look and see what is it about COD that attracts these people. If I had to take some guesses:
- Soldiers are manly.
- Soldiers with guns are extra manly.
- War movies show the action of wars along with a lot of swearing and weapons.
You could probably make the argument that these kids are imitating their "heroes" (just roll with it) and trying to act all macho, but no one is telling them what they're saying is wrong and derogatory. There may also simply be that they're not mature enough to keep their tempers in check, especially if they lose. They may complain about things like lag or glitches. I think part of it boils down to this "Everyone's a winner." mentality in some children's sports.
There also is the problem of consequence. Shooting people in games could be a perfect way of showing it. I know MGS V and the MGS as a whole discuss this, but nothing really shows it, but it would be cool to play a game where you're a soldier in a realistic setting, you kill maybe like 1-10 people in the line of combat, and you come back home.
But at home, you deal with hallucinations, physical aliments (broken body parts, bad knees, prosthetic body parts, being handicapped), post-traumatic event-related stress, indifference to society, a lack of meaning/value in life, anger, indifference to the nation you defended, confusion, and all the other real things that soldiers go through. I think such a game from a gaming "choice making" and "experience through the persons' eyes" experience, if done right, honestly, and realistically, could be a beautiful thing that would be a crowning achievement in gaming.
I mean, if the Walking Dead can have that kind of epic sense of morality and impact, why not a realistic game about soldiers (mostly) after their war is over, and the real war, the war after the war, truly begins=??? After all, it is almost like they went from one reality, to one grim reality, to a grimmer post-war reality, which would be an amazing experience to go through in a video game. Movies have done it good, but gaming could definitely do it better.
That kind of game, if done right, would be an emotional, physical, traumatic, enlightening, and spiritual experience, which is why such games should be made.