I will give this a shot for you. The short version in plain english is something like this:
1. Reg E was passed to protect consumers in the new world (new when the law passed) of electronic transactions
For example the Commentary on Reg E regarding Limitations on Amount of Liability of the consumer says
Consumer negligence. Negligence by the consumer cannot be used as the basis for imposing greater liability than is permissible under Regulation E. Thus, consumer behavior that may constitute negligence under state law, such as writing the PIN on a debit card or on a piece of paper kept with the card, does not affect the consumer's liability for unauthorized transfers.
2. In order for Visa, MasterCard, etc to sell their product their operating rules favor them & their merchants & consumers. For example $zero consumer liability rather than $50 that is in Reg E,
Concerning Counterfeit Cards that you mentioned. For the consumer it is an unauthorized transaction = Reg E protects them.
For the merchant they have a signed receipt and got an authorization through the network = Visa rules protect them.
Even if it is as ridiculous as your customer is John Smith & the signed receipt says Antonio Ribaldi.
SO - net result, because Congress wants to protect consumers & banks want customers to use debit cards (we get interchange income & less cost to process -vs- paper check) & Visa etal want their cards accepted . . . The Banks Always Pay