Civility is completely dependant on the maturity and self-control of the player. Has nothing to do with airsoft per se...that person probably behaves the same way with other things in other environments too.
I've seen the gamut of guys...from newbies to overly-seasoned vets display everything from impecable gentlemanly conduct to raging piss-offs. Not much rhyme or reason to it...it's either in the individual or not. Same goes for confronting an issue (calmly or not) or just "letting it go".
Sure...there are things that trigger guys. Due to airsofts way, way, way less than lethal inherent nature....getting a game where every shot flies true to its mark and every hit ='s an "OUT!" is likely just a pipe dream. Been at some games where it's really close....and it's sweet....