Because it had always been that way, none could think differently. From time immortal, labor was that what did much of the work of production. There is now a generation, maybe two, on this earth, most of whom will never know labor; will seldom see it performed. The energy for their world will not come from the sweat of the back’s of coal miners. So, if it wasn’t (production = material + labor) what was the real equation for production? The input was work, not labor. Today, machines, can and do, do the work. These machines doing the work are becoming more and more intelligent.
Without the help of governmental restrictions on immigration, the unions would never have been able to organize the coal miners; they had no leverage as long as there was a constant flow of poor and desperate immigrants. Point Pinole Regional Shoreline Park is nearby. The Park was once site for the manufacture of gunpowder and dynamite. Originally, the company had been located in what is now known as Glen Canyon Park in San Francisco (owners had one of the original licenses to manufacture dynamite). In 1869, an explosion destroyed every building on the site (including the fence around the plant), killed 2 and injured 9. So, they moved the plant to what is now the Sunset District of SF (area was sand dunes then). Blew up again. This time they moved across the Bay to Berkeley. When the plant in Berkeley blew up, it killed everyone on site. Wound up at, the then remote, unpopulated, Pt. Pinole on San Pablo Bay. The point? They never had any trouble hiring immigrants, mostly Croats, it seems, to work in the plants.