Is it really about morals? I see it more as a service that makes people chose your site over the competition. It basically boils down to “the customer is always right”, doesn’t it?
Morally the customer isn’t always right, but you sell more when you protect them from their own mistakes as well as yours.
The customer isn't always right regardless of metric. That saying is just a distilled version of "treat your customers right even when they're wrong and you will gain more than you lose". But it's a choice the shop makes, it's not a law. And many customers (try to) abuse it.
Morally the customer isn’t always right, but you sell more when you protect them from their own mistakes as well as yours.