Well, to most of you old geezers, I am a kid. And as I've been playing for several years (started at age 12, first game at 14), so I've been on both sides. I feel that younger people playing is completely acceptable. The issue is that kids, more often than adults, is that they believe they are great. Hence the nickname "cod softer". You also get the "mama's boy" who will bitch at everything as he is spoilt, and God forbid he is hit, or the whining will commence. Then there is the "favorite grandchild" (unfortunate for me, as I'm in Florida, the "retirement state"...). These kids are the ones who gets their rich grandfather to buy them the most expensive stuff (worst I've seen is a 12 yo with a post-k£ polestar and custom fitted AATACS, he was bragging it cost over £3k in total... )
But then you get the good ones. Kids who understand that others can know more than them, and who want to learn. I know many kids like this, and I sometimes find the most be more fun to play with. They love running around and being more mobile than some of us, and they are always happy.
So in conclusion: kids get a lot of s*** for being kids. And a lot of them don't help this stereotype. Just like how there are bad older airsofters, there are bad kids as well. So I say give them a chance, and hope for the best