That was not meant to be offensive/sarcastic in any way. I just didn't fully understand your reply and am trying to get it straight.
The MA is always full of newbies or overzealous people. These are the same guys who will chase after a plane that is already unable to remain in the air and steal a kill, despite the warnings from other people nearby.
In a heated chase involving many friendlies hunting a single enemy, KS is often the only thing that keeps these guys from blatantly holding the trigger out to get the kill first. Because KS is so lethal, they have no choice but to watch their fire.
Remove the lethality, and basically KS loses all meaning.
Being KSd by someone sucks. Causing KS to someone else doesn't feel too good either. Thus, if a lot of planes are packed at a small area, people immediately feel uncomfortable about it. They get nervous and jumpy. They try to watch their fire. Since all of them in know about consequences of KS, soon a certain consensus forms that shooting over someone else's shoulder is a very rude thing to do.
Because KS is lethal, a certain discipline is formed between many people competing for a kill. It prevents blatant friendly fire for sake of a kill, and it also prevents wreckless flying(since someone who causes KS to someone else, will immediately face anger and protest from the person who got KSd).