The only thing I find really disconcerting about the 'auto-tip' is that I somehow now feel *compelled* to tip in addition to the 'auto-tip,' as though that amount is not the traditional gratuity, but the minimum. Other than that, it's simple and I think it gives passengers an invitation to discussing any glaring service deficiencies with the pursor...when tha opportunity might not otherwise be comfortable for the passenger to discuss that sort of thing.
By the way, Brigette, you might ask your thoughtful question ("How can you let someone clean . . .and not offer them any kind of money?") to the cruise lines and see whether they have the same sort of reaction you expect of passengers.