As mechanically complex as it must be, it would be outrageously expensive to produce.
As expensive as it must be, it would be low volume production.
Such low volume production would induce an even higher sell price.
With such a high sell price it would be essentially un-insurable.
Being un-insurable . . . well, like all the other flying cars, it ain’t gonna fly.
Cantankerous old geezer goes off, hand props his ole yeller Cub, and goes fly’n.