Government secrecy is a recipe for corruption, waste, abuse of the public, and decisions that protect private interests and violate the public interest. “Sunlight is a good disinfectant”, as a wise U.S. Supreme Court justice said about a century ago.
The secrecy that is allowed under the Access to Information Act is not the only form of excessive government secrecy. Secret lobbying is allowed. Secret investments by cabinet ministers, by MPs and senators, by their staff and by government employees are allowed.
As mentioned before, our whistle-blower protection system is actually protecting people from having the whistle blown on them, as opposed to protecting whistle-blowers who are reporting wrongdoing. All of that secrecy adds up to bad government decision-making.