@CCoyote: I'm sure people who are smarter than both of us have ran numbers and figured that, in most cases, kowtowing to that kind of behaviour is financially in the business's interest since the value of a person's money doesn't depend on their behaviour

Also, brand trust or something. Apparently when you do someone well after a mistake they're more likely to give you a good rating than if nothing were to have happened at all. So for brand-trust it's also beneficial

This shoulda been the other blip