Building the world's biggest high speed rail network and then coming back with flying cars just to flex on the asphalt-heads
Ultimately the problem with quadcoptors is catastrophic failure. Manned or unmanned, electric, gasoline, or dark matter powered. If a quadcoptor has a mechanical failure of just ONE of it's 12 or 16 blades, there isn't a general strategy or design principle that will ensure survival of the aircraft.
In contrast to an airplane, where the wear elements are separate from the structural/airframe elements such that in almost all cases of failure, it's not catastrophic. Indeed most cases of failure the aircraft is recovered (along with all the passengers.)
So while quadcoptors are amazing feats of engineering, I don't think they are suitable for a public transit system.
For that alone they will eventually fail outside a niche product . Give it time once the shiny, jingling keys effect subsides.
Both planes and helicopters are survivable if main engine(s) fail, granted with a few caveats. These things will drop like car batteries from a cliff if they fail.
I would be willing to break the "never get in a helicopter or small plane" rule to ride in this, 100%
