If you are going to make me put a coin into a cart because you don’t trust me to be an adult and tidy up after myself without being nannied, then I am going to do my damndest to bypass your lock and leave a mess out of spite.
In the shops where I am trusted and not required to pay a coin (I never even carry cash these days) I tidy up because that is the decent thing to do.
ahem, that’s PROFESSOR Hanks, thank you very much