I wouldn’t have thought it was hard for someone to think of a good reason for making throwing things off of the top of El Capitan illegal.
Yes, visually it would have been interesting, but really- besides littering, endangering the public (climbers and hikers below), fire hazards (lithium batteries don’t like getting damaged), and all the stupid public stunt ideas it could incite (after the first few YouTube videos of it are posted and become popular), I’m sure they would add a few other reasons for not doing it.
If ever did want to do such a thing like perhaps for parachuting over open spaces, instead of propellers, you could use gyroscopic wheels inside the thing to stabilize it. That way on the outside there’d be no moving parts. Or you could make it a 360 device like they do with those 360 degree throw-ball cameras. They have multiple cameras in a hockey ball sort of configuration and the image is electronically stabilized. That would be cool to view with VR
Goggles!