Separately, regarding the need for regulation in general - while I am no fan of government regulation, I think the FAA made the right call in this case.
Hobbyists generally operate their airplanes in clear and open places, away from population. This is simply because it is more fun to fly your airplane / helicopter fast and freely in the open sky, rather than constantly worrying that you are going to collide with a lamp post, neighbor’s house, neighbor’s head, etc. The larger the model, the more true this is. Once you get above the small electric-powered foam models you can buy at a generic hobby store, pretty much everyone flies either on their own private property (if they have a lot of land), or an organized flying field.
In contrast, commercial use pretty much by definition involves operation in populated areas, or around people. Unless you’re using it for aerial landscape photography, you’re taking pictures of people’s houses, office buildings, theme parks, whatever. And by the time the FAA got around to enforcing their regulations, commercial operators were using pretty serious equipment. We’re not talking about a 12-oz little plastic helicopter you buy at the mall.
We’re talking about a big helicopter (larger helicopters have greater load-carrying capacity and better stability, and generally better endurance), powered by a gasoline or jet turbine engine (electric power doesn’t last long enough, and nitromethane used in hobbyist engines is rather expensive to boot), weighing many tens of pounds, with carbon fiber blades close to a meter long each.
This is essentially a big, flying lawnmower. If you lose control of it and it flies into someone’s neck, it will kill them. If it crashes into someone’s roof while you’re taking pictures of their neighbor’s house, it is likely to set the roof on fire. If you are operating it on a windy day in the summer in Colorado, and you crash it into an open field, you will probably start a wildfire. You can find countless videos on Youtube of fiery crashes of large model airplanes.
Hobbyists do not fly these things in uncontrolled areas like parks, because if you are running low on gas and someone brings their dog in without a leash, and the dog becomes interested in the loud spinny thing in the sky, you have to pretty much choose between crash-landing the helicopter a safe distance away, or taking the chance of severely injuring the dog.
Hobbyists do not fly on windy days. It’s not fun, and there’s a risk of crashing. But if you’re a commercial operator, and you have a contract to deliver the photos in 7 days, and you’re on day 6 and it’s still fucking windy, you’re probably going to take the chance.
Hobbyists can be largely self-regulating. The pressures of commercial operation would lead to unsafe operation without some form of regulation. Either requiring strict licensing standards, liability insurance, etc., or limiting the size and capabilities of the UAVs you can operate commercially without a license.
My guess is that the FAA will set some limits for unrestricted recreational and commercial use of unmanned aircraft, and require that you obtain special permits or licenses for anything exceeding those limits.