They probably did that for a while.
Sadly, they as an agency were un-vettable to the general public, and abused that position to create tons of blatantly unconstitutional programs that they tried to hide.
There are truly evil people in this world, way worse than we probably realize. Our military is not perfect, our country is not perfect, no country or military is, but we generally do our very best to do what is right historically speaking. It's hard to see that if you get lost in the politics of things.