If it happens a few people cannot operate domestic lawnmowers correctly and chase crowds down with them out of acts of terrorism because they slip a gasket, should we have licenses, certifications, and tracking of all lawnmowers? Is that a "no-brainer" too? Maybe we should think first before trying to regulate or educate ourselves out of every edge-case risk.
And the reality is that drone testing and licensing isn't based on hypothetical risks, but real world incidents which have disrupted public safety and caused injuries. So if you have sources for lawnmowers threatening the public safety and injuring anyone outside the owners' household, let me know.
You haven't seen "The Lawnmower Man?" Carry or swing a running lawnmower upside down through a dense crowd, and it will injure many people.
There's also awareness of where you can and cannot operate drones and people should know this. You are after all occupying air space. If drones could only fly up 30 feet it would be a different story but they can go quite far. People fly them over protected airspace, crash them in random places... Last thing you want is people flying them over airports, over busy streets or highways where they can crash into planes, get sucked in to engines, crash into cars and cause accidents, etc etc...
They're not asking people to take hundreds of hours of flight to get certified, just a short awareness course for those who have no common sense... You don't need to blow a gasket to have a drone accident. It's not like drones are crash proof and all aware of airspace restrictions. Just don't want to have accidents in places that can affect others or have people fly them into places that will automatically trigger an emergency responses and disrupt operations and waste time and money... Like a drone over an airport where they'll dispatch security to take down the drone and interrupt all flights taking off or landing. Thats a LOT of money for one person's ignorance or stupidity.
https://www.newscientist.com/article/2190096-drones-are-caus...
I'm all for freedom as long as your 10 minutes of good times don't cost others a ton of money and the reality is there's a ton that can go wrong even with no intent on doing anything wrong.
My coworkers were recently pontificating about how "not for sale in California" is practically a marketable feature on anything with a blade or engine after one of them suffered the misfortune of buying one.
Most everything safety can be disabled if you really want, but anyone pontificating about CA compliant emissions on small power equipment can go sit with the coal-rollers as far as im concerned.
Edit: to stay on topic, if people start getting frequently maimed by drones then I'd expect to see some crazy CPSC action like an altitude safety switch or something...