I coach 6-8 grade golfers and they honestly don't know any better.
Much of it is no one taught them, the adults who did teach them don't know or care, and a minor part from my experience, is they don't give a s*it. Most are "range golfers" with little or no directed course experience. Therefore, It is a very rude awakening for many and their parents.
The most knowledgeable / respectful golfers I've encountered are those who are fortunate to play with their grandparents. Hmmmmm............
I put up with no BS from the kids or their parents. If they are not coach-able during tryouts, they get limited access to the course as we now have a no cut policy. Talent is secondary as I have to be able to trust them on the course as I can't be with 4 groups at one time. They also are privileged to get an hour long speech from me re: expectations before they are allowed to pick up a club. That is a WTF for most of them, but accountability and respect is #1. They either dress and play as "guests" of the course that hosts us or they are forced to skip holes or get reduced opportunities to play.
It all begins and ends with proper adult supervision. The radicals, adults or kids, do not understand or respect the process and the impact of their actions on others whether it is golf or common courtesy. Sadly, it is a "me first world."