Being good at making money with Walmart has nothing to do with whether Walmart destroys small towns. Number of small businesses destroyed is probably a positive metric for Walmart.
What I mean is that he cared about things beyond making money. Early Walmarts were good places to work for and shop at. They were genuinely good for the communities they came to. And they didn't have enough power yet to dictate insane terms to their suppliers either. Back then, they were way better than the alternatives like Kmart and JCPenny's.
I say this as someone who grew up in rural Minnesota (a town of less than 10k), and when Walmart came to my town it mattered a lot to the whole town.
But this stopped being true by the mid-90s (about ten years after he died).