Basic cost - OUCH!
Maintenance & repair - More OUCH!
Insurance - Yet more OUCH!
This won't be for everyman - it's going to be for those who can afford it, and packing that much cutting-edge technology into such a small vehicle is going to be enormously EXPENSIVE.
As has been previously stated, consider airspace congestion, regulation, and so on. And if the traffic behavior around Chicago or other big towns is any indication, taking to the skies in this thing around that town would truly be dicing with death. In some towns there are road rage incidents where folks roll down their windows and empty pistols or revolvers at each other. I wonder what would happen over one such town when someone in one flying car cuts off another someone up there. Ya-hoo, as they say.
Not realistic, for a long, long time to come.