Helicopters, as opposed to this vehicle, have the ability to be controlled even when power is lost. This is a much safer failure mode for personal aircraft then depending on a chute: useless at altitudes high enough to be fatal but low enough to result in a failed chute deployment.

Similarly, winged aircraft can glide, where this one cannot, given enough forward velocity.

This thing will drop like a rock in an incidence of power failure at low altitude and the operator will have no way to control where it hits the ground (for either their safety or the safety of those on the ground).

As far as the flaps, they are not sufficient for controlled flight. Increasing the angle of one of them increases both lift and drag on that wing so you have at best a dutch roll/adverse yaw and at worst a flat spin.