According to you, Walmart employees cannot support themselves, even though we have a raft of labor protections. Walmart is not subverting any labor laws, as far as I can tell.
As to your point about minimum wage: how does increasing the cost of labor ensure that more people will have work? When you are unemployed, you cannot support yourself.
The bottom line is that when two parties enter into a contract voluntarily, that should be the end of the matter.