Those arguments are not interlinked with each other. The minimum wage is what it is and Walmart compensates their employees based around those perimeters. If the minimum wage became $50/hr tomorrow, then everyone else would start making $150/hr and the cost of a gallon of milk would go up to $35, accomplishing nothing.
So, separate the minimum wage debate from what employers actually pay their employees. Then understand that skill decides your salary, regardless of what the minimum wage is.
If i create a company selling post it note greeting cards and it becomes a multi billion dollar industry, i should still be able to pay people a fair wage for their ability to sign a post it note, regardless of what my profit margin is. Business owners reap the benefits of profit margins.... not burger flippers or shelf fillers.