I have registered to protect my license. Now that the FAA is involved my modeling activities, I have to conform to the regs, or I'd jeopardize my certificate and that's how I make my living. Because I fly RC. As stupid as it sounds, or actually is, the fact remains that some peple actually stand to lose a lot if they do not comply. Guys like me, and I can't afford to give away pay because of this.
Like Dan says, and Sean Elliot is to have expressed, this will change a lot when commercial operators increase ops. The model thing might go completely away. There were several iterations of specific rules of light airplane visual flight rules after 9-11 until they finally decided, or arrived at the fact through finally reading them, that rules already existed for operating visually and in instrument conditions of all airplanes so the specific after 9/11 rules are now referred to as temporary rules. Same may happen here.
I don't think a vast number of FAA people know what control line actually is, anyway. Or... have the power to answer the question of whether they are exempt or not.
Chris...