Why would an airline be any different than a hamburger stand?
For many reasons, for exemple:
if you are a Mac donald's employee, forgetting the big mac sauce when preparing this hamburger will have very little consequences on the customer.
If you are an airline employee, forgetting to lower the gear may have huge and definitive consequences on the customer.
When you are in the transport industry (Boat, train, airplanes) you are responsible for the body and the saoul of your customers, just because they actually have to come into your vehicle.
Making money whatever it takes doesn' t apply to the transport industry.