I certainly can't argue that these folks earn their money, and that it's about time that the guidlines for tipping are raised. However Carnival should also raise their saleries. This is the guarenteed portion of their pay. Of course we DO NOT KNOW that Carnival has not given real raises. My dancer daughter has recieved raises during her 10 years of service. Some were general base pay raises and others for longevity and good reviews. I will have to extrapolate that the wait staff has at some point has had a base raise also.
I will still tip extra when it seems right. And it usually does.