Perfection will suffice
Some good points noted here.
It seems a lot of this has to do with (a) attitude, (b) situational awareness, and (c) culture clash.
It should be made clear that no genre of paintball has a corner on honor or dishonor. There are good sports and lousy sports in every aspect of this game. There are sponsored teams who are an absolute joy to play with, and first time walk-ons who are an absolute nightmare.
I've been apologized to profusely by a sponsored 'agglet' player who accidentally double-tapped me when we shot each other out, and who then apologized again back at the tables. I've watched a 98C rental-toting adult first-timer stand over a little kid huddling on the ground and shoot him continuously point blank in the back and neck until a ref (and the rest of us who saw it) bum-rushed him. It was horrific, and the guy was just standing there laughing as he blazed away, and was totally bewildered at our fury when we pounced on him, having evidently no earthly idea how much pain he had just inflicted.
I've played with agglets who wiped, and those who didn't. Same with mil-sim folk, and same with renters.
Some people have a clue, and honor, and some are simply ignorant, and some simply can't be bothered with either.
Moreover, some folk don't seem to know where they are, and who they are with. If a player is in a tournament with real lucre on the line, then they had better take it seriously. But to then take that same aggressive mentality (which is good and even necessary on the tournament field) and apply it to a group of birthday party walk-ons, is stupid, embarrassing, dishonorable, wrong.
In the same way, if I am a hard-core milsim player and I and my friends are in a military scenario game with other like-minded hard-core milsim players, then it's fine and dandy to dress the part, and play the part, full tilt. You should, in fact.
But to then behave in the same way with the local church group renters is stupid, embarrassing, dishonorable, wrong.
You likely wouldn't show up to work in a football jersey, reeking of beer and buffalo wings, any more than you would show up to a Super Bowl party in a suit, tie, and toting a briefcase.
It's a case of not knowing where you are, and with whom, and then, on top of it, not caring to find out and adapt in order to be a good sport.
If the birthday party players are agglets in training, and want to run full-tilt, then great. Same with the milsim folk. But don't show up and expect them to be just like you, or want to be or, failing that, to have to endure you being that way with them.
So in all cases, the problems that occur are usually when someone is playing with the attitude that the universe rotates around me, rather than taking the time to see who is on the field and how I can adapt my style of play in a way that I can still find enjoyable, but that also serves to improve the enjoyment of other players, even if (shudder of shudders) they play a different style.
At the end of the day, we are playing one of the most perfect games ever devised. A blend of chess, tag, hide-and-seek, capture the flag, dodgeball, and squirtguns. There is arguably more variety in paintball than in most other sports.
There is certainly room for players of different styles to play nicely together, at least once in a while.