Question? Do Aldi's and Trader Joe elsewhere have the coin (Quarter) lock on the shopping carts?
In Britain Aldi and Lidl stores have always had this and the other store chains are using trolley retention schemes of various kinds. Tesco have started using trolleys with a locking device - if you take the trolley outside a zone marked with a red line at the boundary, a wheel locks and you can't push it any further.
One problem is that some people (mainly chavs) don't just dump the trolleys in the car parks; in urban areas they push the trolley to their home. Kids use them for rides, they end up in alleys or in the street, or in canals and rivers. You can tell the rough end of town by the dumped trolleys. The town litter people or the supermarkets have to collect them, which costs money. Sometimes people steal them altogether and use them for hauling stuff about, like building materials.
Some towns have bye-laws - for example in Leicester if you are caught dumping a trolley outside its owning supermarket's boundary you can be fined 80 pounds (about 135 US dollars).