The problem is that most shopping we do is one-off, as opposed to being a recurring customer. For example, if you're selling bread, your potential customers are 1000 locals and if these 1000 locals decide your bread sucks, your business goes belly up. But if you're selling ice cream in a tourist destination, then you'll never see your customers again even if your ice cream is so good it causes instant involuntary orgasm, so you have zero reason not to scam them.