And to add insult to injury, that kind of risk is entirely the fault of the payment industry itself, for failing to implement sufficiently robust security measures. And yet, the merchant typically carries the risk, not the payment industry.
Perhaps any compulsory refunds should be classified as either based on fraud or based on dissatisfaction, and the card payment services should be required to indemnify the merchant against fraudulent ones provided that the merchant has followed the recommended security steps before completing the transaction.
In fact, I've noticed recently that a few payment services are offering to eat chargebacks based on claims of fraud if an on-line transaction included a test such as Verified by Visa, so this situation may be starting to change, albeit rather slowly.
For losses based on dissatisfaction, it's probably as fair as anything practical to make the merchant carry the risk, but it is extremely unlikely that this kind of chargeback would result in a sudden spike in refunds a long time after the initial payments. It seems reasonable to handle this case via a level of retained funds commensurate with the observed level of loss.
That really only leaves catastrophe-scale events, such as a product having a fundamental flaw where everything dies at midnight on 1 January 2000. But in that case, either the business has the funds to cover the loss (in which case there's no problem and the card services can go to court if the merchant doesn't pay back what they owe) or the business is toast (in which case unless it's a very small business, probably no individual who gave a personal guarantee could do much to cover the costs anyway, and if it was a very small business, there's no substantial danger to the card service companies on the relatively rare occasions that they have to write the client off and eat the loss themselves).
In short, to the individual a piercing agreement may be an existential threat to their way of life, but such agreements make little real difference to the card companies in cases where the problem is not essentially their fault anyway.
