WM and MD jobs are not there for you to "actually live" on them, most of them are not. WM has over 2,000,000 employees, those are starter jobs, as in: you have no skills, you are at the beginning of your professional career, or maybe you are a new immigrant and need the first job in the country, type of jobs.
They're not really what you believe they are. You clearly have never worked in such a place before. The minimum wage plus erratic hours is designed to ensure that you're stuck working there, it's difficult to find the time to seek out new jobs if you're also a student, parent or both. The mere fact that there are people at Walmart who have worked there for over 20 years in a low-end, low-wage position proves your point utterly false.