The only thing which I take super seriously in airsoft, and will piss me off to no extent, is when the dead talk. I don't particularly care if you're a goofball, nooby, or dead serious milsimmer... shut the fuck up after you call hit. I have literally been in a room (behind a door that opens towards me) , at night, had an entry team come in, I kill them both, had them apologise to me (wtf?) then tell the next entry team where I was as they left.
On a side note, Im not quite sure how serious some people take training, but there are groups of likeminded individuals, and if you train, they will notice.
Ár skal rísa, sá er annars vill
fé eða fjör hafa. Sjaldan liggjandi úlfur
lær um getur né sofandi maður sigur.