"And he does have a point: the President (and Vice President) need advice. Some of that advice will come from people with a chicken in whatever fight is going on, because they're the ones most motivated to gather information on the subject. This and similar demands, if acceded to, will have the effect of foreclosing that information source forever; the result will be that anyone who knows anything about the subject is absolutely forbidden to offer advice."

If this is information, why isn't it made available to the public?

What secrets are there that can't be released?