The 18+ rule is ours alone. We can't expect everyone else to abide by the airsoft scenes generally expected practices.
Its great that we have self-policing and it does - I assure you - reflect upon our scene favourably with authorities, but there are many more clear softs used stupidly every day that we just cannot control.
FWIW, it sounds Warbird like you understand and appreciate the rules and even risked flammage to get your story off your chest here. I'm glad to hear there are responsible younger players willing to pass down the voice of reason - please continue to do so. It makes a difference.