I remember the big production Carnival made out of the Paradise initially being a smoke-free ship, even during construction the workers were banned from smoking on or near the ship. Then they were quite strict with the guests, even booting wedding couples on embarkation day once or twice for violating the policy, among other guests who pushed the envelope.
But just a couple years later they moved it to California and quietly dropped the smoking ban like it never happened. I think at the time the story was Carnival was not making as much money from Paradise because it attracted the types of guests who also didn't gamble or drink much. Remember, at the time it was the only mainstream ship to ban smoking. Renaissance cruises were no smoking but also priced out of many people's budgets and mostly in markets you had to fly to, mostly in Europe. So the bottom line won out and the ash trays were laid out on the bars and lounge tables.