flying a kite can be dangerous. This device is, according to the inventors, classed as a kite for the purposes of US legilation. Because it is tethered. Better to allow something that is safer and reduce the need for other types.

There are many ways a kite can be annoying, one of them is the Japanese variety that tethers multiple kites on each other and even in the UK can exceed the 500 ft legal limit for such things. There was a case in the 1960's near Heathrow Airport. And doubtless many more since.

Putting a camera on kites and helium ballons is done by estate agents but not as controllable. If anyone bothered to view the video, you will have seen the inventor's raison detre was to enable the videoing and photographing of events like the demonstration against electoral irregularities in Russia. Which would have recieved better world coverage with more photography.
And look what that irregularity produced with Polonium in London, and tanks in Ukraine and who knows what else.