I think there has to be at least little more to this than that. There's some complicated implications taking this to logical extremes, what of the adult industry for example? But really, it's hardly a stretch to say the whole theme around which these cafes operate is degrading. Typically cafe work doesn't require a worker to behave or be encouraged to be objectified in this way and in a normal cafe context, most of the whole maid cafe schtick would be considered pretty inappropriate.