The problem with this kind of simple story is that it removes wages from the equation.
Americans line up to mine coal in the dark underground. They don't do it because they like the dangerous and unhealthy work, but because it pays good union wages.
Americans put hot tar on roofs and pave roads in the desert, not because they like the work, but because they like the wages.
Pay high wages, and Americans show up for work.
If wages go up enough, companies are incentivized to mechanize, either fully, or partially.
Look at these workers. They are carrying their picking trays down a row. If higher wages were paid, a conveyor belt would float over that row, with workers dangling off the side to quick pick. That's a better job, with more mechanization, and better pay.
The argument that these are jobs American won't do is the same one once used to justify slavery: "No free white man will pick cotton."
In fact, when slavery was abolished, mechanized cotton pickers entered the field, driven by free men who were paid better wages.