We don't have flying cars because people are fucking dumb, and because the viable options are loud as hell.

We absolutely have the technology, and if there were a drive to make it affordable there would be more significant research into doing so.

To do a flying car, you need to simulate friction in the air, with significant enough force to prevent colision, while also maintaining low enough noise pollution to be acceptable to the average citizens. This second part is why we don't have Personal helicopters, despite aircraft being relatively affordable (in my cursory search I found two Helicopters less than 200K, one barely more than 100k, if there were significant drive to make them mainstream for the public they'd presumably be much cheaper, benefitting from economies of scale.)

Additionally, how do we as a society handle ATC for flying cars? Emergency stops? Impromptu repairs? Birds in the props‽

I'm not trying to naysay the retrofuturistic image we all want for the world. I am saying it probably shouldn't include flying cars. Especially if they're just Personal quadcopters.