Probably (a) they're all out of puff after removing the outermost packaging and protective styrofoam from large or bulk purchases and strewing it around, or (b) the remains of their spilled or half-eaten food-court items have left the cart too icky to deal with.
In some instances it is complicated by (c) the person who has traffic backed up halfway to the street while waiting for someone to leave Just The Right Parking Spot is making things too crowded and dangerous to get back to the cart area.
Well, he *meant* to push it halfway up the curb right in front of his own car like everybody else, but the sidewalk was already full of other shopping carts.
Anyway, it's good hard data for the social sciences. How far is too far to go in extending courtesy to others in a public place? About twenty feet on average, is my guess, if you're pushing a shopping cart at a big-box store.
Don't even get me started on the people who abandon their dead batteries, bleach bottles of presumed-toxic petroleumesque who-knows-what, old tires, or in some cases their entire defunct car (not to mention the ever present diaper)...
Renting 300C, Magnum or ChargerDori A Schmetterling With what engine? 3.5 or 5.2? LOL. You think 3.5 is a large engine? You guys in the UK have mostly engines...
--Joe