People's imagination is dumb. They picture cars ,the annoyance of being stuck in traffic, see all the empty sky and think, hmm, you know what would fix this, flying cars. But imagine that world, with millions of flying cars, and it'd be 10 times as awful.
What they fail to realize is how bad air congestion would be. Airplanes landing need a lot more separation than cars. Parking lots that now have 4 entrances/exists will need to share 1 with 10 neighbors.
I think the only way flying cars will work is if humans are taken out of the equation as much as possible.
Robot flying cars would still be awful. The car noise and pollution is already insufferable, now bring it overhead. And the fallout of an accident are already grotesque, now multiply this by 9,81.
Flying cars are a fetish: because they are futuristic technology, therefore they are desirable. That is the motive force behind them.