That's partially why it's hard. People are automatically unhappy if their flight is delayed, their bags take time to arrive, they have to gate check a bag, sit near a baby during the flight, etc. It would be very hard to run perfectly with the weather being such a large input factor. Even food tastes worse up 35k feet due to the lack of moisture and air pressure. Think about how unhappy people would be with Apple if every time it rained or snowed, the phone couldn't function due to physics?