I'm one of those people who feel that your pay should not be based on how many hours you work. What people are paid should be based on the skills and responsibilities required fpr the job, the education level needed for the job, and what the "market" decides the job is worth.
If a person works 40 hours at their job and can't afford to live on that, then they have a responsibility to themselves to find a different job that allows them to do that. I do not believe a company should be forced to pay anyone a living wage just because a person works 40 hours. I also believe that doing so will only create more part-time jobs where companies stop hiring full time employees, which benefits them in 2 ways since they will probably no longer offer benefits such as healthcare, paid time off, 401K matching (and pensions if they even exist anymore). Then what, is that better or worse?
This used to be relatively fine and dandy when the economy was different, when there were more manufacturing and skills based jobs, when an education opened many many doors. But this just doesn't reflect a Tertiary economy. About 80% of the US economy is now based on the service sector, yes, 80%. Many of those jobs, tens of millions of them, are minimum wage, or low paying jobs, and many of them don't require any high level of education, or skills. They require some on the job training. Now, those jobs are still difficult, you still work HARD. As just about anyone who has ever worked in a fast food joint will tell you, its not an easy job, its physically and mentally demanding (and I have worked in both a lumber yard, as a professor in a University, and in fast food). When 10s of Millions of jobs do not require education or high levels of skill, its just not as simple as "find a better job" because you will always need those tens of millions of people in those positions. For someone to move up and out, someone else has to move in, potentially down and in. The economy isn't one of infinite upward mobility, its a pyramid. The base level with lower pay, fewer benefits, is wide and deep, as you move up there are fewer and fewer jobs. For every person on the top, hundreds of thousands, millions even, have to be on the bottom.
The fact that you think people who work 40 hours a week, and can't afford to live (so they probably do more than just 40 hours) are going to be able to afford to just "find a different job" demonstrates you have never had to live like that. You don't have a clue what its like to live in poverty, especially as a member of the working poor. When you are working 40 - 80 hours a week, having to walk and or rely on (usually awful) public transit, and still manage all your home responsibilities and personal care responsibilities, you don't have the TIME to search for another job, and you don't have the money to take time off work to go to interviews, or to "just move" as so many with your vision of the job market like to say.
You simply have an unrealistic, and unsupported by fact, view of how the job market and the economy works.