But it does answer the only really relevant question. If not for the desire to disarm law-abiding Americans, the BATFE would not exist. Any evil which results from the existence of such an organization is quite predictable.
Your attitude seems to be that the superficial goal of disarming criminal Americans has a value which could justify its existence. I believe that your premise is wrong. Do you really believe that the BATFE has ever benefitted you by disarming a criminal?
The BATFE exists. It will exist for the foreseeable future. Wishing upon a star doesn’t solve any problems.