Believe me, if it weren't for tipping, you would have to clean your own room and serve your own food. These people work very hard for the recommended $3.50 each per day for the steward and waiter and the $2.50 for the assistant waiter. They also work at least 10 hours per day, seven days a week.
There is no such thing as a minimum wage for these people, but with the tips and no expenses, they do make an excellent wage for the countries that they come from.