I don't believe it's some work ethic that is at issue. It is a 'if your ass isn't in the seat you're not making me money.' It's the same reason sick time in the US is so low, why vacation time in the US is so low, why showing up on time is so god damn important and why any activity that isn't making you or your employer money is looked down upon as a waste of time.
In many ways, the US economy never grew out of the slave labor mentality.