If it was as easy to get in an aircraft and fly it as it is to get in a car and drive it, then I would agree that the crah safety standards should be the same. However, in the aircraft industry, the efforts are concentrated on prevention rather. This is why anything involved undergoes rigorous testing and regular inspections. This is as true for the pilots as it is for the aircraft. Our training and preparation is far removed from the amount of training a car driver gets. And we are under constant checking and verification.
Also, aircraft undergo rigorous checking and testing, as do the great guys who maintain them.
I don't think the weight penalty of impact protection systems, and the financial penalty in terms of getting a new system trialled and approved, and the on cost, would prove to be worthwhile.
The number of people killed is, still, extremely small. And whilst every death that can be averted is obviously a worthwhile goal, as with all things in aviation it comes down to the trade off.
Someone in another thread said today "nothing that is worthwhile can ever be 100% safe". Whilst I can see this is no comfort to anyone who has lost friends and/or family, the tota numbers killed are so vanishingly small that I think we have the approach just right.