[Makes it harder for the merchant to steal from the customer.]
I’m not sure it’s intentional. The thing is - given the pay levels at retail - they’re not getting the best. This shows up in price labels on the shelf, which aren’t kept up to date when they should be. Some of the time, I elect to not purchase some items if the price is way above what I saw on the shelf. Hard to do that if you don’t know what showed up on the cash register. I don’t think retailers in general make it easy for customers to see what items cost as they’re being rung up by cashiers. No percentage in it for them - taking items off may require a manager’s approval, which slows down the line.