When you're talking purchasing, logistics, inventory replinishment, etc., those WM folks are the hands down champs. Right now few can get a product from Asia, or wherever, into your hands for less.
I'm seldom in a WM, but I do go to Sam's and notice they hire many special needs folks who would be unlikely to get a job with a small, family owned retailer.
I've never blamed WM when the new WM Supercenter at the edge of town causes small shops on the town square to eventually close. The blame goes to the local citizens. Shopping at WM instead of remaining loyal to Andy and Barney and their chums on Main St was the choice of the local citizenry, not WM. Don't want a WM in your area? It's your and your neighbors' choice. Just don't shop there and they will go away, guaranteed.