All of these offerings from Uber appear to exist solely for pumping up the stock price. The flying taxis thing is, quite obviously, not going to happen for the

All of these offerings from Uber appear to exist solely for pumping up the stock price. The flying taxis thing is, quite obviously, not going to happen for the reasons you say, and a number of other reasons (proof of flight worthiness will require very significant testing time). It's not really worth taking any of these ideas seriously. All they illustrate is that Uber doesn't believe their core business is viable.