Betcha the boys in WW2 wish they’d had those kind of rules.
Let's look at a typical trip, which at my company tended to be a 4 day trip. You want good productive trips, but you can't always get them. On a 4 day trip let's say I have 6 hours of flight scheduled each day, or 24 hours scheduled that week. I am getting paid the better of 24 hours or the actual flight time. Now let's look at my duty day. For a 6 hour day with 4 legs it was not unheard of to have a 12 hour duty day.
So now for a 4 day trip, I'm "at work" 48 hours and being paid for half of that. Now consider that I'm not going home every night and my trip starts at 6 am on Friday and ends at midnight Monday night -- that totals to 90 hours away from home.
How does this compare to a 40 hour work week in an office? In that case you are on duty 40 hours, getting paid 40 hours (or salary) and if you have a 1 hour commute one way, you are spending 50 hours away from home.
Back to the flight schedule. A given month will have trips less productive than 24 hours and although you can probably build a 96 hour month if you tried, the average line of flying is typically going to be 75 hours of flying. You can ballpark that will equate to 150 duty hours and 300 hours away from home for the month. Extrapolate that to a year, and you have 900 flight hours, 1800 duty hours and 3600 hours away from home. I would say this represents the average US domestic 121 pilot. Some do more, some do less, but this is pretty typical.
What do we do with all of that duty time that isn't flying? Let's see: · Eating · Updating charts · Checking the weather · Checking the paperwork · Coordinating with gate agents, ramp agents, fuel agents to make sure we leave on time · Programming the FMS and getting our IFR clearance · Preflighting the airplane · Postflighting the airplane · Doing the weight and balance · Sleeping
Note, that all of these activities require we are at the airport, in the secure area and we are not being paid. The pay clock starts (roughly) when the airplane is buttoned up and the parking brake is released and ends when the parking brake is set and main cabin door opened.
They were at war, there were men on the ground who would likely die if they didn't fly. The consequences resulting from them not flying because they hadn't had any sleep in the last two days were a bit more important than an airline pilot not agreeing to fly extra because their company was too cheap to have enough reserves to cover the sick calls.
If a military pilot in wartime doesn't fly then people die. If an airline pilot doesn't fly then United doesn't make as much money as they otherwise would, the Smith family is a few hours late to the beach, and some traveling salesman has to spend a couple of hours more spending his expense account at the airport bar. The two situations aren't even remotely comparable.