OK first if you are standing around like a high school hall monitor asking people to return their carts you have waaay too much time on your hands. Get a job or a hobby.
Second its not a crime to fail to put the cart back. Its the polite thing to do and most of the time we all do it. But once in awhile I’ve been known to wedge it on the curb myself.
If you think I’m an ahole on FR you should see me when accosted about a shopping cart return at Kroger. 😉

You are a stupid, annoying, or detestable person. I did call you that name, I defined you.
Not putting your cart in the corral is similar to refusing to queue up in a line and crowding to the front or burping or farting in public or talking on your phone on speaker or laying across several seats on a crowded bus or train.
It is low trust society / high time preference / 3rd world behavior.
People who act that way are low class a-holes.
....and it actually would be crime if the cart got lose and hit someone’s car.
Flagging someone with a gun isn’t a crime either but if you accidentally shoot them, it becomes a big problem.