Any comparison of the CAA with the police doesn't hold water. The police do not make rules and therefore nor do they need to explain them. The police do not examine people and organisations for their fitness to operate. The police do not grant and oversee approvals to operate or to educate and nor do the police issue licenses to anyone, a person or a body. The CAA have the power to withdraw or suspend approvals and licenses but the police do not have any such powers. The CAA may prosecute in a court of law but the police cannot.
There is every reason for the CAA to explain itself, it's rules, it's actions and decisions. They have a duty to educate in all of it's areas of responsibility because no one else can.