That's a one sided view of it. Credit cards increase customer spending behavior which benefits merchants. For low end customers, the appeal is access to credit, either long-term or just in between paychecks. For high end customers, the appeal is the rewards and perks they get, and the convenience and safety of payments.
This is why you are most likely to see credit card surcharges for tax payments, court costs, and other non-discretionary charges. Anything that either is optional to pay, or isn't but they really want you to pay now (ex. a debt collector) has every incentive to subsidize the card acceptance fee as it will increase their sales.
This is why you are most likely to see credit card surcharges for tax payments, court costs, and other non-discretionary charges. Anything that either is optional to pay, or isn't but they really want you to pay now (ex. a debt collector) has every incentive to subsidize the card acceptance fee as it will increase their sales.