Isn't it sad that we can't have an exciting new technology because the threat that some outsider will blow themselves up? Is there really nothing we can do about this, either now, or in the future?
Very few people actually blow themselves up (terrorism is really really low on the list of the most common causes of death) so I doubt that it will be why we don't have flying cars.
Self driving flying cars (which will be essential for mass market adoption) make an excellent weapon. No one needs to blow themselves up, just the car.
As far as I know terrorists have no problem blowing themselves up.