Store 59 is also sort of a special case, in that when they leased their first building for it in the '70s, it was at least twice the size of anything they'd leased before, and became the proving ground for their Supercenters. And they made a point of rebuilding and reopening the second building on the site within 6 months after it got destroyed by the 2011 tornado (granted, that was easier since they didn't lose much of their employee pool (no one was killed in that Wal-Mart, but I'm sure some moved away because of the housing shortage), they were all very busy at the 2 other Wal-Marts in the area in the interim).
To provide a personal anecdote, one of those multimillionaires was my father, who in the early '60s was a low level manager at a Ben Franklin "Five and Dime" (https://en.wikipedia.org/wiki/Ben_Franklin_(company) ) in Joplin when Sam Walton, who owned a set of them down in Arkansas, would regularly drive up to Joplin for airplane trips. He'd always stop by and talk to the owner and managers of this (set of?) Joplin (area?) Ben Franklins, getting a feel for what was going on here. Very smart guy (certainly smarter than the Joplin owner, who declined the offer to invest in Walton's new venture...).
Stepping back to the general question, the crime patterns in Joplin area's four Wal-Marts pretty much match the neighborhoods they're in. Before anyone can claim Wal-Mart is doing a bad job here, they've got to correct for that.
Although I can't speak to the stories people are telling of poorly managed ones, only that I've never seen or heard of such here, the stores are well run and to my observation, pretty much all the employees but some of the cashiers are reasonably happy/satisfied with their jobs/whatever.