I agree with the driving IT guy example. I used to be a technician who would travel via plane to another state to fix "broken" production lines for pharma companies. After I made the fix, they would have me sit in the cafeteria for two days doing nothing but drinking coffee and reading the paper (pre-smartphone era). When I told the plant manager I felt guilty about sitting around doing nothing, he said that the profits from 5 minutes of the production line running paid for my two days of doing nothing. So it was worth it for them to pay me to hang around just in case there was another problem.
THIS, and it applies to far lower tech than modern pharma. A century ago, one of my grandfathers was a blacksmith in a little farming town, which had a little canning factory. During harvest season, when that factory was running 24-hour days, grandpa was paid to sleep there every night. Canning food is a complex, time-sensitive, and safety-critical activity. If production is halted even "briefly" - you may have to start throwing out large quantities of spoiled food, waste more time re-sanitizing things, etc.
