You're argument is that a "fully transparent" system cannot work. Which as far as I can tell is a straw man, because I can't see that anyone has claimed everything should be fully transparent. Can you point me to a system which is dangerously close to being fully transparent?
Government secrecy is an incredibly convenient method to hide the unethical and the illegal, and governments by their very nature will always strive to keep you in the dark as much as possible. "Why do I have to be groped at the airport?" "Can't tell you." "Why not?" "National security." See how that works? When everything is secret, you don't have the right to protest anything.
Some amount of secrecy is necessary, just as it is necessary among moderators on the forum. But if moderators never had to justify anything and always said "that's classified", would that make a good forum?