As someone who worked at more than one grocery store where the manager scheduled more people per week if someone needed to constantly be on cart duty (e.g., during the winter, because folks were less likely to put their carts back during the cold), I often don't put my cart back in the correct spot. I do so because at the stores I worked at, that would help people who want more hours be able to make a case for those hours to the manager. I often had to do so when I wanted more hours, and I was the person who did the carts. I never do this when cart duty is otherwise hard (e.g., late at night, in the cold, in the summer heat, etc.)---in those cases, I always bring my cart back inside of the store and put it completely away.

So, yes, but there are sometimes reasons to do something besides what's courteous.