Great question! Honestly I believe that there are fundamental safety and reputation issues with travelling by air that are simply too difficult to solve in the near future. I also believe that the market for aviation has settled at near daylight-robbery levels, and there is not enough pressure from competition to drive this down to the level where we'll be parking aircraft in our driveways anytime soon.

To elaborate on my first point; Cars are devices of inertia... you press the gas and go forward, you press the brakes and stop. You are only ever fighting one force... which is the momentum of forward or reverse travel. You can mitigate the damage that inertia causes by using seatbelts, crumple zones, airbags, and headrests.

In an aircraft, you are always contending with gravity. This is a much harder puzzle to solve, as it is a constant form of acceleration that you can't resist against. And more importantly, it is always potential energy while your machine is running, but becomes kinetic very fast when the machine fails. I believe that the reason that flying is seen as unsafe and not commonplace is that when your machine breaks, you don't come to a stop but rather begin accelerating towards a very sticky situation.

EDIT: This isn't even mentioning weather considerations, traffic direction, and enforcement all of which pilots train for years to understand and integrate to. Also, we monkeys can barely stay focused and resist distraction when travelling in two dimensions... we really don't need a third.