[avcloudy]

You're making a feely argument for a phenomenon that has evidence. The evidence is that there's a max amount of work you do per week, and the more you work the less you do per hour - and that max amount is below 40 hours, incidentally.

There's effective evidence that people who work 6 hours a day are more productive than people working 8 hours a day, and after 4 hours of active practice, you aren't getting any better.

And on top of this, perpetually tired and exhausted people are not at their best.

Regardless of whether or not you accept that someone working 41 hours really isn't doing more work than someone doing 40 - you can see that two people working 30 is much better than one person working 60. Working people for long hours is mismanagement, at some level.