Earlier quoted context omitted.
Why? If it's understood that the way the system works is that it's in your 'virtual cart' as soon as you take it off the shelf, why isn't it the customer's job to put it back if they don't want it anymore? There are other checkoutless systems that use the customer scanning a barcode as they pick up each item; same deal there.
Why is it the customer's responsibility to figure out and comply with the rules of your (nonstandard) system to avoid getting charged for something they don't intend to buy and didn't in fact use or take out of the store? There are all kinds of reasons why that is unreasonable: * different stores might have systems with different rules and policies, causing confusion; * people may not remember where to return the ite…
Because that's the store's policy. If you don't like it, nobody is forcing you to shop there.