I'm not sure why airlines should be excluded. They were the "growth at all costs, we'll make it up on volume" business of the 70s and 80s. More capital invested

I'm not sure why airlines should be excluded. They were the "growth at all costs, we'll make it up on volume" business of the 70s and 80s. More capital invested than ever returned over 40 years. Other businesses like this: franchise restaurants (many, many failed), motels, car rentals (you can see the gold rush in supporting the new tourist economy back then).