People feel more stress at work because companies are more demanding because of global competition.
And they find they have more workload for the same amount of pay. So this is, I would say, something hidden behind what is called a tight labor market. The affinity for four 10-hour days makes sense to him. For people working on salary, most of them work 10-hour days already, so they might as well go for the day off. But he doubts that manual laborers would see it that way.