It's important in this instance to distinguish how wolverine876 thinks the system should function and how the system is intended to function. It's possible for it to simultaneously be the case that you hate the system and that the system is working as intended.
In the US the people elect a government, the government passes laws creating rules (or passes laws delegating rule-making authority which is functionally the same thing) for, among other things, how information gets declassified. That information then gets declassified or not in accordance with those rules.
> we don't know what we're missing.
That is literally always true, it's impossible to prove that the government isn't hiding something.