The purpose of putting them in the "cart corral" is so they don't roll into your CAR and scratch or dent it when either it is windy or some "kind" person bumps into it with their bumper so they can have the parking space where you so thoughtlessly left it. When that happens, you won't be thanking all those "kind" people for leaving them in an empty parking space for you.
They BELONG in the cart holder
with the understanding that in some cases it isn't physically easyand there is little choice , but generally they are the exception. That's part of the reason PUBLIX offers to take your stuff out to your car and take the carriage away for you.