Thats the real world, the retailer sends back to supplier gets a refund then sends that to you. They dont get penalized for shipping because you had it posted out rather than walked through the door. At the end of the day the retailer wasn't to blame either.

Shipping wasn't faulty, it is a consequential loss, and nearly every item is excluded from consequential loss of the product being faulty.

Ebay force return shipping as its not their money, its a good selling point for them, and because they can. Some sellers would do it anyway as good PR, but the benefit of that PR is lost if everyone is forced to do it. It then becomes expected rather than just good service.