What GP is arguing is that is achieved by fixing the pay distribution, not by limiting hours. If you only limit hours but don't fix the pay problem you create perverse incentives where people have to work undocumented "overtime" or face the threat that they will be replaced by someone who will or where people who want to work overtime face punitive punishments if they do so.
One thing I can be extremely clear on is that I do NOT think the US government legally limiting work hours is any kind of solution. I am all about looking at society as a whole and reasoning on society-wide changes we can make voluntarily to achieve a better world.
Unfortunately any kind of solution that tries to address the market side effects of labor will die in the US by the socialism boogeyman
To be clear, I am talking about a voluntary system. No one would be prevented from working more, it just wouldn't be necessary to survive. I love to work pretty much all the time, though only some of that is hours I am billing to my employer.
EDIT: I quickly rewrote my original comment after posting, but I do see one quoted reply got in before the change. Just wanted to add this note about the change.