Personally, I feel it is an indirect way to tell adults/parents they should be donating, trying to shame them into doing it.
I agree and was thinking the same thing earlier today. They are getting at the parents through the kids.
Perhaps they are also trying to build for the future since little kids' money means nothing now, but when they are adults with jobs they will be trained to give - that is however many of today's kids are left in the organization in 20 or 30 years, probably not that many, but there will be some.