I think there is some room to narrow the exemptions and be much more specific, especially given the passage of time. That is sort of theoretically taken into account in the act as it stands, but it really isn't exercised to any great extent.
I certainly see a need to protect the some information, current information, because there are bad actors, but what the system seems to neglect is the fact that what might be sensitive today is much less sensitive 20, 30 or 40 years later. There has to be some mechanism to recognize that evolution and, even for information that is currently significant, I think there are probably some ways to narrow the scope of what is truly sensitive and what the bureaucracy would prefer others not know about. There's a difference between bureaucratic desire for confidentiality and true threats to national security.