What do think it actually costs Princess to provide internet, drinks, casual dining, etc... on average, each day of a cruise?? If a passenger pays $60 per day for a seven day cruise, the total is $420. Over the course of the seven days, let's say 40 drinks are consumed and a couple of pizzas are eaten. Internet is probably less than $2 per day, drinks cost $2 each and the entire rest of the Plus Package is probably not costing more than $20. So, the total cost to Princess for the week is 7 x $2 plus 40 x $2 plus $20... a grand total of $114!!! Plenty left over to make contributions to CA pool, take a profit, etc....
Even though I fabricted the numbers, I believe the service staff and bar staff aren't being short-changed by Princess as a result of passengers choosing to purchase packages.