a growing number of children have their accounts, not only the monkees. A lot of parents have setup accounts for their children to use now and for the future. They see them as an investment on the Steem platform.
With the boys doing YouTube channels they could upload their videos to D.Tube to earn a bit of Steem, they could also use castr.io to stream to both Steem and YouTube at the same time through Vimm.tv. There is DSound for Apollo's music.
The Steem ecosystem is growing rapidly. The opportunities to try new stuff and earn tokens is growing along with. Did you know that by installing Actifit on their phones they can earn Steem and Actifit tokens just by walking and playing?
As for Spunkee Monkees, I'm one of the adult mentors called Monkey Pals. TeamHobo has children from Ireland, Indonesia and the US involved. It's a great way for the kids to get to know each other. So while parents agree to oversee the account, there is a benefit for the children to have their own accounts, they get to establish their online identities while having fun with the app. BTW, I did need a separate account as a Monkee Pal, it's just the way the program is developed.