One of my autistic and/or retarded theories is that stuff like this is just glow ops by Big Box Store Business. When I worked in retail or grocery stores, I loved running the carts back in. It gave something other than the monotony of the shit drudge work you normally have to do, got you outside and away from the customers, and you could easily stretch it into an unofficial 20 minute break if someone left a cart in the hinterlands of the parking lot.
My theory is that some CEO at Walmart wanted to squeeze some more efficiency out of the workers and started this trend of "civilized people always return their carts" via social media and memes and faggots like this rather than let their employees have an extra smoke break. No one cared about where you put your cart 10 years ago and now we're acting like a bunch of dumbasses over it.