Wal-Mart’s business model of “everyday low prices” is dependent upon eliminating the inefficiencies from the entire supply chain, it must consistently offer the very best price on every product it sells, and the only way to do that effectively is to relentlessly cut costs. Vendors that can make themselves efficient enough to supply the system are rewarded with vastly higher volumes, but you can’t make up a loss on volume. In the world of Wal-Mart, only the most efficient vendors survive, and they do so on razor-thin margins.
Becoming a Wal-Mart vendor is a matter of choice. If a company can not become efficient enough to compete head-to-head with the most efficient vendors in the market, it shouldn’t agree to supply Wal-Mart. Period. “Wal-Mart or nothing”, however, is a false proposition. If you don’t like their low-price strategy, pick another one.
In the same vein, becoming a Wal-Mart employee is a choice. There are a lot of other companies that pay ~$8.50/hr if that’s the economic value of your skills. Stocking shelves is not a skill that is difficult to acquire, nor is there a shortage of people in the world willing to do it. Don't expect Wal-Mart to pay more for anything than it's worth, including labor.
Continuing to purchase products at Wal-Mart is also choice. If you don’t like the company, for whatever reason, don’t shop there. You vote with your dollars.
Wal-Mart has gained its economic power due to massive productivity and efficiency gains developed by employees who chose to work there, selling products produced by vendors who chose to supply them, sold to consumers who chose to buy them. It’s a choice-driven model.
I understand the unease of dealing with such a large economic force. The complexity of the issue is immense, and it's easy to see aspects of the company that don't point to utopia. But it is unjust to imply that a company is a threat to the community simply because it does not coincide with your ideals of human and societal development, whatever they may be. It appears that Wal-Mart's economic clout is a matter of justice, the justice of the aggregation of free and voluntary choices of consumer, vendor, and employee that we commonly call the free market.
Prove Wal-Mart used force or fraud against any individual (consumer, vendor, or employee), and you have a limited case. (Which can be settled in a court of law.) Otherwise, you have no defensible reason to call foul.