What would happen if everyone stopped tipping would this result in self service (I think not) or stamp out slave labour as they would never get anyone to sail on them unless they paid a decent wage. Maybe it is the passengers that are to blame for this. Just looking at these modern blocks of flats seems like you are enclosed with no views of the oceans like the old ships but contained in a steel cage full of ways of extracting the most out of you. I think that they still promote the old idea of a leisurly stroll around the deck and laying back in a deck chair watching the ocean go by while being served a cool drink. Doubt that happens now.
That's the way the mop flops.
My thanks to Brian for this site.