Earlier quoted context omitted.
You ignore the article's point about the risk of choosing a proffession. For example, what's the return on investment for the worker that trained to be a professional car welder in Detroit? I don't know if "-100%" captures the loss.
This is an apples to oranges comparison. You're bringing up losing a job and comparing it to losing an investment. In this case the investment is gone, and the FUTURE earnings of the worker from that specific job are gone. The worker already received compensation for past work. However, there is a point to be made about how the loss of livelihood, or a reduced standard of living can be devastating. It's just not the…
You're discounting the time it takes to learn the skill. That training is worthless to the worker now. It's an investment that is gone.