Karen,
You do pay for it either way - it's not free! Regent just doesn't itemize it on your bill - they include it in the fare. Oceania is supposed to be changing the policy on it according to the Cruise Director. And unlike HAL or RCCL etc, the prices were very fair - they did not price gouge because you are a captive audience. Water was $2.50 and a Coke can $2.00. Perrier $2.50 for a small and a Pelligrino (Large)is $3.00 - very fair compared to a restaurant charge and far less than the RCCL and HAL price of $4.00 for a bottle of water.