The media should have access to many things about government, but it should not have access to “everything” about all aspects of government. There are many areas of government that should not be accessible to the media either for privacy reasons or for the sake of national security.
For an example of national security issues, there is no way that the media should have access to information about exactly how the government runs things like espionage or like protecting the president. If media outlets were to print things like the plans for protecting the president or like the names of our agents in foreign countries, it could lead to very negative consequences for our country (and, of course, for individuals such as the agents).
As an example of things that should remain private, imagine the case of someone on Medicare. Since that is a government program, its records would count as things “about the government.” But this program’s records will also have a great deal of personal information about a person’s medical conditions. That sort of thing really needs to be kept confidential.
So, while most things about the government should be accessible by the media, not everything should be.