The real reason is that we don't have one-person aircraft that can stop and hover with <300ft stopping distance and is under 10 ft wide. Helicopters come close but they're expensive and I'd hate to see parking for such a model of transportation.

Helicopters aren't really allowed to fly over most areas in cities though, except for police and other emergency helicopters. The noise and danger make it a no go, even if they were smaller.

Helicopters can fly wherever they want, barring the same restrictions that apply to fixed-wing planes. For the most part, there aren't really any helicopter-specific restrictions.

Yes, but this doesn't really help the case for flying cars either way.

Edit to clarify: Presumably you'd want to land your flying car almost anywhere in the city; this is not going to happen anytime soon, for the same reasons that helicopters and planes can't.

Buzzing should emphasize the loud freaking noise these things would create landing, taking off, and flying at low altitude. Annoying to say the least. What we don't need more of is noise pollution.