Why do you keep blaming the restaurant? They are under no obligation what so ever to accept credit cards. It's your fault for not knowing that before you ate there.

Did every other table have the same problem? I'm betting not. They took the few minutes to see what the policy was, were cards accepted, what cards were accepted, etc before they sat down and ate a meal.

This has nothing to do with the restaurant, the dishwasher, or your waiter (who you stiffed by the way). This is entirely because you didn't do your homework first.