OMG Costco is the worst for that, completely oblivious, GET OUT OF THE MIDDLE OF THE AISLE!! It's like merging on the freeway, same people. What is going on in that tiny little brain?
Yep, leave our cart in the middle of the aisle, blocking dozens of people, while you stand in line to get a piece of waffle.
I now just ram/push the abandoned cart to the side to clear the aisle.