Usually kids learn new things by seeing them with their own eyes. Any place kids go to, may learn new things from both sides, good and bad things. Most of the times when kids and grownups like specific person from tv or real life, they become behaving similar to them especially kids. When kids go to a movie or theatre, their families or grown up people who they went out with are responsible to choose the type of movie or play of they were going to a theatre.
In the old days most plays contain good information in the beginning, the middle and end. Unfortunately these days most of the plays ( not all ) just have a good ending by the good or kind person always beat the bad one. The kids plays should contain many good behaviours in the beginning, middle and end of the play because most of the times, most of the audience are kids.
As most people know kids learn quickly from others if they like the such as a celebrity, this is why actors should always behave in good manners on stage even if they are the bad guys. Being an actor in kids plays is simmer to having a child of your own but for few hours only.