The Damage of Card Rewards

Yes, but "No way, that is, unless merchants started giving us all discounts for using cash instead of cards." This assumes using cash is cheaper and in many cases it is not. Merchants don't have to accept credit or debit cards however, most prefer it for a verity of reasons.

Edit: You can't just take the direct cost while ignoring the opportunity costs of the other solutions. As for the cost to consumers of all the card use, the National Retail Federation figures that the so-called interchange fees that their members pay to accept Visa and MasterCard alone cost an average of $427 an American household in 2008. Do you think amazon.com would have lower costs if you had to mail in cash to pay for your order? Also, without the protections a CC provide I would never buy anything from an online store that did not have a seller reputation.