Isolationism in local communities

Los Gatos used to be a rural town many years ago, but has been growing in population and rising in income. Today we see the lengths parents go to in this small town to isolate their children from young adults who are themselves children of a varying maturity. In this article, you can read about the attitude of parents which in my sensibilities represent paranoia. I guess the point of having the Venue is to provide a place for kids to go out and be entertained, but not be associated with young adults who are older than 18. Kids naturally want to be with older kids. Young adults seek independence and naturally are drawn to older peers because of their experiences. It's futile trying to separate them. It would be wiser to simply instill common sense and values in your kids and thereby inoculating them from bad behavior and poor judgement. Separating the younger kids from the older ones merely create a lower class and that's how many kids will see themselves. The rebels will surely act out in defiance just the same. It seems many parents want society or community at large to take on each parent's given responsibilities; protection, education, and moral upbringing. Proscription is always an easy step to take, but applied against human nature nearly always fails.