Suppose today that someone has skills that provide "utility gained by the [prospective] employer" (what I'd call "true worth") of $4 per hour (and it's not for a restaurant position). Is that person, today, able to get a job paying that $4/hour? No, they aren't, at least not legally.
Why is that? Because the minimum wage law takes that option away from them, increasing unemployment and increasing the underground, untaxed, unregulated, no worker protection or benefits economy.
I am perfectly able to find people today who cannot find a job, who are neither psych nor substance impaired. Convenienently, you say that temporary unemployment during the economic downswing "doesn't count, obviously." I am more inclined to find that statement disingenious rather than obvious. When times are tough, one would expect that wages might come down. When the natural market wage would be lower than the minimum wage, some of those jobs will naturally vanish. How is that to the advantage of a job-seeker?
If you know someone who's labor is worth less than minimum wage to employers, consistently over a period of years, then that satisfies what the author was saying, that they can't find work because there is a difference between their work value and the minimum they can be paid.
However, temporary economic hard times are more like a mismatch in the number of people available to do work and the positions available. For example, if the coal plant in your county runs out of coal, there are no coal mining jobs, no matter how cheaply you will work. This doesn't prove anything about the minimum wage.
Since you can't find anyone who is unable to find work due to their labor being worth less than the minimum wage (even digging holes or lugging sacks of concrete pays way more than minimum wage) either the minimum wage is so low that it is moot, or other effects dominate any theoretical 'person worth less than minimum wage' effect in practice.
It shouldn't be any surprise that demanding physical labor jobs do in fact naturally pay more than minimum wage. Lots of people have physical limitations that prevent them from lugging sacks of concrete, yet they need and can afford things built with concrete.
If minimum wage is totally moot as you argue, what is the downside to abolishing it? It does not require someone to be consisently un or under employed over a number of years to prove that minimum wage laws contribute to unemployment.
Being out of work for 6-12 months, but willing and unable by minimum wage law to work for $5 an hour to put food on your family's table, would be a substantial and avoidable hardship.
Fortunately, in the real world that doesn't actually happen much, because those enterprising hard-working people can find under-the-table paid-in-cash work.
Why is that? Because the minimum wage law takes that option away from them, increasing unemployment and increasing the underground, untaxed, unregulated, no worker protection or benefits economy.
I am perfectly able to find people today who cannot find a job, who are neither psych nor substance impaired. Convenienently, you say that temporary unemployment during the economic downswing "doesn't count, obviously." I am more inclined to find that statement disingenious rather than obvious. When times are tough, one would expect that wages might come down. When the natural market wage would be lower than the minimum wage, some of those jobs will naturally vanish. How is that to the advantage of a job-seeker?