The viewpoint you're talking about is a common one in BDSM. In rheotric, the submissive is a sexual toy and at the sexual pleasure of the Dominant. In the mechanics of the relationship, though, the Dominant creates scenes in which much sexual pleasure is given to the submissive, and a good Dominant will incorporate the submissive's fantasies into these scenes. In the process, the submissive completely relinquishes his/her power to the Dominant and is, thus, free to feel, enjoy, and focus on the sexual experience. In scenes where the submissive experiences a series of powerful orgasms, s/he may go into a sense of euphoria called "subspace." As this is so enjoyable, submissives may want to have sex quite often. This is one reason a submissive may be called a "slut" and/or "whore." However, in the BDSM world, these are terms of endearment, not derogatory. Perhaps, it is the idea that sex is to be celebrated, so wanting to have sex often would be a good thing, not a bad one.
Imagine that - no guilt about sex and having a lot of great sex. Makes being called a "slut" or a "whore" much easier to take, I would think.