I don't think its so much as younger players don't have respect as it is they don't have experience with the consequences of their actions yet. Something that only life experiences can provide as you age.
That and they don't usually have the means to transport themselves further out of town.
Actually when i was 13 I was playing airsoft with my spring guns and the police were called. They actually took away our guns and impounded them and sent them to me in the mail lol...
Oh and about the transportation thing, thats basically the biggest problem for airsofters under 16. WE CANT GO ANY WHERE. And it sorta makes me angry.