My experience is that if a cart is left in the lot, another customer is willing to pick it up and use that cart. A quarter profit and no change digging.

And the quarter is somewhat annoying at times, but regular shoppers often make sure they have on in their car. In addition, there are often folks willing to trade a quarter or make change and the cashiers will often make change as well. If all else fails, they are usually located in locations with other things nearby, so you can buy something smallish and be on your way with the shopping.