I think all of this is easier to understand when you think of a central fact: these testing regimes aren't designed to "clean up the game" or anything else. They only are there to clean up the image of the sporting body involved. The NFL testing regime is a joke. Everyone who wants to know already knows the entire league is juiced. But they can catch the stupid or careless player every once in a while, parade him around as an example in the public square to show how tough they are, and go on doing what they're doing.

The MLB isn't really interested that much in catching everyone using steroids; they're just interested in people *thinking* that they are. So to take Braun up on his offer and expose their system as flawed would go against the entire point of the exercise.