First off - not a retail employee.
Untidy carts in the corral, for some reason, annoy me. Even if it takes a few minutes to sort them, for size and straightness, I have to - much to the annoyance of people who are waiting for me to get back to the car.
I guess it's irritation at the bad people who cba to be considerate to the cart collectors. Ffs you aren't doing someone's job, you are making their lives a bit less shit for 30s of effort.
And I bet he says that with a straight face...