I'll agree that minimum wage is not only on "the low side" but is criminal --- but I'll constrain the urge to "go political" on this board.
Here, I merely raised the contrast between the service one recieves at a "self service" restaurant from that recieved on a cruise ship (even the worst of them). At worst, the cruise ship service beats anything I've seen on land, any where in the US. Sure, I'll tip for that --- if its is not included in the fare. Heck, I even tip 15% to 20% for lesser service on land. But will I tip for "self-service"? Oh, no! Who do I tip, myself?