I find this topic very interesting, from what I've read thus far it appears a lot of the older folk would rather not bother with the youngin's. Being a parent myself, I find it is my duty/obligation/responsibility to raise my children in accordance with the right moral tools, so when they come of age they can be properly integrated into our society. I believe the same should apply to Airsoft.
Now, keep in mind. I have yet to play a single game. With that said, I can't argue the game related points. However, I strongly feel it is our responsibility (those of us who do have kids) to show them the proper way as a few you mentioned prior. This website is a fountain of knowledge when it comes the sport. And I thank my lucky stars for finding it! With that said, would it not be possible to throw out the proper instructional information for the under age kids that do wish to take part in the sport. (I'm sure this topic has been covered from head to toe).
Just a Father's 2 cents.