[wahern]

The carts still need collecting. And at least when I worked at K-Mart in the 1990s, there was no dedicated cart collecting person; it was the task of whoever had the free time, usually someone handling stocking, typically junior, and especially someone young (though these days they have the electric carts).

What you were told sounds like one of those slightly tongue-in-cheek excuses people sometimes use to justify behavior, though that doesn't necessarily make it insincere. For most of high school I worked dishwashing jobs. A typical task for a dishwasher includes picking up trash in the parking lot. People throwing trash in the parking lot weren't doing me or anyone else any favors.