Generally, we live in an era when parents -- and some players -- expect a coach to run a team as if the team existed to suit the moment-by-moment preferences of that one player and his parents. 40 years ago, your own parents would have nipped this in the bud. Today, the parents are often the ones leading the charge in the opposite direction.
I'm not sure if the explosion of travel ball in the last 15 years has fueled this, or if travel ball just sees the same thing for the same reasons. But it occurs to me that after 6-8 years of building the expectation that the team exists for the player's individual benefit, it can be hard to turn that battleship around and get parents to understand that it is the obligation of the player to serve the team and not the other way around.
But if kids don't learn this as young as they once did, they'd better get it learned in high school, because carrying the narcissistic approach into adulthood, while all too common, inevitably leads to a lifetime of frustration, anger and failure.