The link you provided mentions this in an odd way:
> With a single engine helicopter you don’t have this redundancy. However, on engine failure, the single massive disk of the helicopter is an asset. ... Close to the ground, this stored kinetic energy can be traded, through pulling up the cyclic, to allow a safe landing. This is called autorotation, and is practiced by all helicopter pilots.
The air taxi that succeeds, at any sort of scale, will not be meant or designed for skilled helicopter pilots pulling levers, at the right moment, as they speed towards the ground. They will be dumb, cheap to service, unskilled to fly, and have more than one point of failure.