This is the core problem with leftist social engineers.  They ignore the intrinsic nature of man.  Man's first instinct is self-preservation.  This means that he will alway choose what is best for him and his family first.  Obviously Walmart is paying their employees competitively or they would have no employees.  Employees work there to further their own self interest.  People shop Walmart because it is also in their self interest to keep more of their limited capital.  
If you are wealthy enough that you do not need to shop competitively, there are plenty of stores for you.  If you are dissatisfied with your current job, improve yourself and get a better job.  This is what living in a free country is all about.