Considering that sometime, in the beginning, the Waltons started with little or nothing, and through very long hours, hard work, smart business, investing in themselves and in their company, the business expanded and prospered beyond their wildest dreams, and is now a staple of most communities nationwide, I don't see how you cannot say, "Good for Them". That's what America is about. Same thing with Bill Gates. People may hate Microsoft and how he runs it and how it controls the market, but he built the business from the ground up. "Good for Him". And if someday you build that better mousetrap and find your worth in the Billion dollar range, Good for You.
Consider also that the profit margin on anything you purchase from Wally World is razor thin. On groceries, it's less than one percent net profit. In the rest of the store, the margins roam around in the low single-digits. The only reason they're able to have such laughably-low margins and still reap a handsome return is the profit of SCALE. And it costs billions to build a retailing chain of their magnitude, and in so doing, creates lots of construction and supply jobs.
Wal-Mart has negotiated very very low prices from its suppliers - who then are rewarded with far more units sold than if the prices were higher. Yes, you as a supplier, might only make a few cents on each bottle of salad dressing you sell to WM, but since they buy 80 million bottles of the stuff from you every year, WHO CARES?!?!
Michael