A number of people get their kink from what is generally described as degradation / humiliation. As a practical example, a slave/sub can be forced to show her self off in a slutty way in public. Or even in private, some people consider it degradation or humiliation if the dom is calling the sub a slut/whore/fucktoy/...
I also like to see and treat my partner that way. But I somehow fail how that would be a degradation. To me, my partner that is making herself available to be my slut/whore/fucktoy is worth more than before. So from my point of view, this is not a degradation from the previous status, but actually a promotion. The latter is worth more to me than the former.
So once again this shows the true meaning of the word perverted. What some people or maybe even the general public considers to be worth less, I consider to be worth much more.
The same happens to good girl vs. bad girl. To me, my partner is a good girl, if she's nasty, kinky, perverted. On the other hand, if she were to ignore her kinky side and prefer to be vanilla, she I would consider it a bad girl.