YES! I'm sorry, but I think people that leave them in a random space are just lazy. Sorry, my opinion. And if you have a child, leave them in the cart, wheel it to the cart return, and carry the kid back.
If you're in a hurry and someone is walking past, ask them if they need a cart. I've done that many times when I see elderly people. I'll take their cart off their hands and use it in the store. They appreciate it.