I think they were worried that if Australia stripped them of their charitable status other countries, particularly those in the Commonwealth or those having problems with the Orgs attitude to CSA, may have followed suit.
It's such a red herring for the org to say they don't have the organizational structures in place to work with children. Witness kids are routinely baptised. Once baptised a witness is obliged to participate in the preaching work, in conjunction with the congregation, in order to remain an active publisher. They are also given other assignments by the congregation ranging from talks & meeting parts to cleaning etc
It's true these things aren't specifically for children. In fact children are expected to work to support the congregation in the same manner an adult would, these activities all being directed by the organization.
So I feel witness children are a good deal more vulnerable in many ways because they are given no special consideration, do not have their own activities and are expected to take the same risks an adult would.