But if you really think about it, the Apollo Program was run very Agile-like. If it had been Waterfall, then Apollo 1 would have been destined for the moon. But instead, there were several 'flights' that never left Earth, several more that were unmanned and fully automated, then there were LEO flights designed for figuring out how the whole command module thing would work. Then they changed the whole schedule at the last minute because there was no LM's available to work on rendezvous maneuvers in LEO and instead sent Apollo 8 to the moon and back. And when they did land on the moon, they did it with a minimum load compared to what the requirements said, just as a kind of proof-of-concept. In between each flight, they talked to the users, made some changes based on the evolving needs, and then moved onto the next set of requirements. Okay, so they probably didn't have a scrum meeting everyday... but for such a hugely complex development effort, they understood the values of prototyping and iterative design, something that apparently is lost in most government contracts today.
IMO it doesn't have much to do with availability of guns either- my dad talks about how he used to go hunting in the morning, throw his shotgun in the car, and then drive to school. Guns have been readily available for a long time.
The real issue to me seems to be lack of respect for authority, caused by lack of discipline. It used to be that the threat of detention was enough to stop most fist fights from ever happening. Not because detention was particularly effective, but because telling Mom and Dad would lead to more, and more effective, discipline. There used to be an understanding that expected behavior and accepted behavior were two different things. So yes, boys will be boys was expected, but the acceptable behavior was reinforced by authority figures (principals, parents, friends parents, random people on the street who are older than you and saw you do something you shouldn't be doing). Now, accepted behavior is always expected, and any deviation from that must be the fault of some outside influence. Don't try and discipline the child, try and find who/what else to blame. Must be the principal/parent/friends parent/random person on the street who is at fault.