Get a grip. We are talking about toy quadcopters, not military-grade autonomous vehicles. A certificate of airworthiness for a six-inch quadcopter? A license to fly an RC toy? I'm sure you're also an advocate for licenses for kite "pilots" too.
Yeah, I can imagine your next argument too. "I mean the six-foot hexapod copters carrying three cameras and FPV downlinks." Your problem there is using the nebulous and incorrect term DRONE to lump everything together. If you have a problem with six-foot professionally manufactured multi-rotor vehicles, THEN SAY SO!!! Don't lump everything from a smartphone controlled toy from Fry's together with a heavy-lift multi-rotor carrying a Sony HD, gimbal mounted camera package.
Most people are familiar enough with cars that they don't get their knickers in a twist about regulating every wheeled vehicle the same way. We don't worry about Tesla cars driving on off-road trails and we don't allow quad utility vehicles on the freeways. To call every multi-rotor air vehicle a Drone is like calling every wheeled vehicle a Horseless carriage. And seeking licenses for every version of multi-rotor vehicles is like requiring a license for roller skates.
If you really want to discuss COA and licenses, then be specific about what class of air vehicles you are talking about. I don't have a problem with licenses and COA for six-foot, eighty pound camera platforms that will be flying over property and people. I understand that if they crash into a crowd then there is a real potential for injury. But a 12-inch, two pound toy with a pin-hole camera making videos for Facebook and YouTube worries me about as much as a badly thrown Frisbee.