It doesn't seem like that long ago but I guess it must have been just shy of forever...

When I was little, it was not entirely uncommon for strange adults to feel perfectly comfortable in chastising nearby children. It might be verbal, it might merely be a look. The thing I remember about this was that all adults, but especially parents, were automatically on the side of the other adult. The child who brought about a rebuke was automatically wrong.

At least, they were wrong then and there, in front of the other adults. It wasn't the case that all adults agreed on everything. Rather, it was that certain things were more important than other things. One of the most important was harmony. There was a sense of 'we are all in this together' that fostered cooperation with others and a minimum level of respect for others.

By way of example - my parents may have tolerated a certain level of rambunctiousness in our play. So long as we were not actively interrupting nearby adults, our noise could go to a certain level without inviting their attention. If, however, some new adult felt our noise was a bit much and said something about it our parents would immediately adopt that new level and enforce it. They would tell us to quiet down or go play somewhere else. That might seem inconsistent of them, but it actually wasn't. We learned the lessons early on. The lessons weren't about what level of noise was acceptable but rather about paying attention to the reactions of others and learning to modify our behavior in reaction to those. The lesson was about consideration for others and achieving harmony in groups. And, to be fair, it included a bit of that old-fashioned "children should be seen and not heard," "father knows best," "respect your elders," and etc.

A side-effect of our special snowflake approach to life is a distinct lack of civility and cooperation. Everyone is entitled to an opinion and more-so everyone is entitled to voice that opinion, loudly if they desire. This entitlement has rapidly spread to include all education levels, all ages. No one is required to defend an assertion; in fact, the opposite is true, we've now extended this entitlement all the way to saying we have a right to not even be challenged on our beliefs, as arbitrary and ill-founded as they may be.

We've traded harmony and cooperation for an outsized sense of self-righteousness and entitlement. We've elevated the individual above the common. My right to be heard trumps anyone and everyone else's right to a peaceful moment.

Screaming and cursing in a park? Of course. Who cares who else might hear so long as no one infringes upon my right to say? What did those kids really take away from that encounter? Was it merely about the appropriateness of cursing or was it something more damaging?

Another adage that has gone out of fashion is, "it takes a village to raise a child." That implicit understanding that we live in a society, that other opinions are valid and valuable, went the way of respecting elders at about the same time that 'stranger danger' replaced 'if you ever need help, find an adult' as the most common advice given to children.

This is one of the few TIFU posts that don't leave me full of pity for OP. Kinda feel bad for the teenage boys with the great role models though.