I'd agree with your last point but only if reworded slightly: "the law should only rely on standards that are freely published." To me, this is where public.resource.org is barking up the wrong tree. The obligation to ensure free access to the law rests squarely with the government. It's not ASTM's duty to allow free access to standards that the government incorporated into a standard. If the government wants to use copyrighted work, it should enter into appropriate arrangements with the standards organizations that produce it.