Technical: Drones are a neat way to use your technical acumen to affect the real world. Making a python script look for prime numbers is kind of neat, but making a python script cause a robot to fly around and pickup trash in your background is so much cooler. People want to have drones remain legal because they want a cool technical outlet to use their skills on.

Effectiveness: When they outlaw drones, then only outlaws will have drones. Wait a second, the outlaws already have drones, so if they make drones illegal then they're not actually doing anything but causing problems for law abiding citizens. The criminals will continue breaking the law.

Liberty: Combine the previous two and you get liberty. Outlawing drones will not be effective in protecting citizenry or the interests of the state in serving the citizenry. Owning a drone is pretty cool. If there is a cool thing that I can own AND me owning it doesn't cause effect the well-being of my fellow citizens then a state that is interested in freedom and liberty will allow me to own it.

On the other hand if the state is interested in oppressing the citizenry, then outlawing drones would be an acceptable action to take.

Personally, I would rather live in a state that tends towards enabling liberty in the citizenry instead of one that tends towards oppressing the citizenry.

As somebody who flies UAVs for a living, I can say that whenever the laws squeeze tighter, it doesn't really seem to make a difference on the recreational side, but the number of hoops that need to be jumped through on the commercial side go up. For every recreational/bad-actor that does something dumb, I know that I will be punished by the overseeing bodies and made to explain why I won't do [irresponsible thing | illegal thing], plus will have more people in the public with a bad perception of my work, despite the amount of safety precautions I take.