Why Jim? Those people work for tips. Tips aren't included in the fare. As I say to Frank, when we travel now one bag is included and the second has a charge - it's just part of the cost of travel.
If I pay a bit less on the whole cruise and then I can decide if my $10.00 drink is really going to be $11.80 - I can decide not to order the drink and the cost of the cruise is less. If you go to a bar to have a drink, do you tip only on the first round of drinks or on the entire check? They just add it for you when you have your drink!