Mmm, I used to do steel historical reenactment, and lost teeth and fingernails to that without complaint. But the goal was always to minimise pain and injury, and due to the hand-to-hand nature of the activity, anyone who couldn't or wouldn't restrain themselves was very quickly identified and invited to sod off.
Airsoft however lends itself to rogues, with some degree of anonymity and plausible deniability, and the ability to inflict pain without serious injuries meaning it's usually shrugged off.
I'd really like to see much more pro-active marshalling on MEDs, overkill, or shooting dead players: and no, it's not "just part of the game", it's the difference between everyone having a good day, and only the sociopaths going home with a grin on their faces.