What I gather left and right, and from the story linked, is that in the US, working more hours does not equal more income. Maybe if you're a freelancer that can charge by the hours, but given the US's horrid worker protection, what is an employee in the US might as well be considered a temporary freelancer in other countries.

I'd probably work Saturdays if I got paid by the hour, but at the same time, if I did and it was a decent income I'd probably opt to work less - and I don't even have a family.