I agree to some extent. There is a term Walmart scale, and it is defined as things that have a 1 in 1,000,000 chance of happening happen 10 times a day at Walmart.
Walmart is targeted, for example, there might be 2x as many Walgreens or CVS locations, but while their revenues are $100-$150B Walmart is closer to $500B and they have 100,000,000 customers enter their stores every week and that is attractive to criminals. Also, I want to note, Walmart shoppers are a much larger cross section than just the poorest of society, in fact you can easily find stores where the average income of their shopper is $80k/year.
Walmart is a target for all kinds of crimes, from their parking lot to shop lifting to cons. I was recently in Bentonville pitching one of my side projects at their HQ, and this topic came up, one ongoing scheme currently taking place consists of a group going into stores with fake documentation from HQ (complete with fake Bentonville phone numbers and fake voicemail) and they literally set up a photo portrait store inside the Walmart in-store leasing locations. Walmart customers are going in and getting portraits done and the group just closes up shop and disappears (the irony, not a single Walmart customer has complained about their experience).