because they do have a hierarchical system that allows adults to have charge over children who aren't their own. Insisting that children be always involved in activities with unrelated adults was always going to create a vulnerability.
They also don't recognise children as children - expecting them to "keep up" with the adults. In terms of trying behaviour standards - such as long hours of meeting attendance even on school nights. But also adult mandated activities e.g. preaching to and with strangers and arranging and giving talks with unrelated adults.
Children get zero consideration due to their age so why would watchtower prioritise their safety?😡