To be fair, the MAJORITY of fraudulent debt being charged off by banks prior to the liability shift was as a result of negligence or human error at the retail location. Yes, this means that the banks were eating massive chargeoffs that were no fault of their own, nor avoidable by any reasonable means by the bank.
Furthermore, most retailers and retail finance institutions have a profit sharing agreement so if fraudulent charges are being written off, it's going to impact the gain share on the back end for the retailer. The retailer is losing the money regardless.