I like knowing where I parked. Further, we have something called valley parking, in most places that I would want to get off for a while.
You wouldn't need to know where you parked: a quick text message retrieves your car.
I will get to the airport after all. The only difference, I can have one or two to relax at home with wife, before the flight. The end result for the self-driving car is identical to the cab case, you can still have your drinks because you will not be driving the car. However, removing the cabbie from the equation will cut costs dramatically.