It might be regional.
I can definitely see it here in western Michigan, and I think I know why. Folks are convinced that WalMart always has the lowest prices, and you know what, they probably do.
Thing is, we've had Meijer around here for, well, at least 50 or 60 years. It's pretty much the same thing as a WalMart with a nice grocery story inside. Guns, ammo, hardware, clothing, etc. It's got everything and the prices are pretty darn good.
Meijer has greater penetration in this area. A Meijer store is 5 minutes from here. WalMart is 20 minutes. In fact, I've never lived anywhere in my entire life where a WalMart was closer than a Meijer.
Now, I value my time, and gas costs money, I'm smart enough to realize this, so I always shop at Meijer.
The folks that can't figure that out are all hanging out at WalMart, and it shows.
I'm not saying everybody that shops there is there for this reason, but if you're a high school dropout with 3 kids, a loud mouthed wife wearing clothes 2 sizes too small, and a rather large collection of NASCAR branded clothing, well... I know where to find ya.