Exactly.
No kid will sit infront of a PC and surf the forum for doing posts and earn bitcoins, they will sit and play games or watch movies or something like that.
Kids are mostly lazy about such things, like reading posts or writing posts and also kids won't be able to do constructive posts of any kind i guess.
Unless the kid has a really high IQ, a sociopath and spend the whole day on the Internet. Unfortunately though, most kids don't think of earning money because its their parents responsibilities. Imagine why would a 12 yr old kid go to the Internet and search how to earn money. Why would a kid try to learn all these bitcoin stuffs? I think it is either he/she is curious or because his/her parents aren't responsible enough to give him/her enough money to live a good life.