This has the effect of making people even more dependent on college, btw. And can effectively make certain types of career paths disappear entirely.
Thing of a greeter at Walmart. How easily can Walmart just do away with greeters?
1. There exist jobs that are not worth paying someone X/hour, but are worth it at some number less than X. For the purposes of this discussion, X is "a livable wage".
2. There exist people who work, but do not need to X to survive; retirees who just want to be out of the house, mentally handicapped individuals for whom being out doing work and meeting people is helpful, etc.
Those two points are facts.
Requiring that every job pay a livable wage means that the combination of the above two will no longer be available. Those jobs just will not exist if they need to pay that much. As a result, some subset of group 2 will no longer be able to work (this part is opinion, but seems a reasonable conclusion).
So, the tradeoff is being made to make live worse for some of those people in group 2... in order to make life better for people in a different group. That may or may not be a good tradeoffs. But just the fact that it exists as a tradeoff means that "no job may pay less than a living wage" is not a black and white topic; there's a grey area.
But to take your implication head on, I once worked for a company whose owner decided to do this stuff himself.
It resulted in several instances of people going unpaid for a few days and the owner sending out an email basically saying "if you don't get your paycheck on this friday and need money, come talk to me, I'll fix it".
The result?
The owner finally started paying someone who was competent enough to ensure everyone got paid on payday!
These laws exist for a reason, and those reasons generally involve people being affected by it.
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My learnin's from watching all of that happen is not to take it lightly.
Or maybe not depending on how much I cared about the company, but most likely I would.
So for these companies, it's required.