As someone with 45 years in the front line of aviation I can only say wow, what condescending posts by B2N2! I would be inclined to remind him/her that the self loading cargo PAY aviation Gods like him/her and his/her employers for a service and, regardless of the reasons, if the promised service is not provided, they have the right to complain if they feel inclined to do so!
Not all self loading cargo are holidaymakers by the way!!!
The argument that aviation is a complex house of cards holds true for a great many industries too. Aviation is indeed in that category yet we in air traffic control never cease to hear pilots constantly bitch about ATC primarily because, with some exceptions of course, most of them don't have a clue as to what a complex house of cards ATC is!