Oftentimes it's to protect secrecy.
As a small historical footnote, when we were talking about making government records available after 30 years, in the post-war period there was discussion in cabinet about this. One principal reason they didn't make it 25 years was that men in public office could still be in public office after 25 years. There was a desire not to embarrass those individuals.
We're really talking about embarrassment here more than anything else. We're not talking about good government. We're not talking about democracy. We're talking about, in a lot of cases, simply the desire to protect public officials from embarrassment.