I don't know if you were around for the glory years of Saturday Night Live, when it was actually funny.* One bit that was notorious was Dan Ackroyd and Jane Curtin in a "Point/Counterpoint" segment on Weekend Update that invariably included the line "Jane, you ignorant slut." (Curtin would rebut with "Dan, you pompous ass.") People were actually scandalized by Ackroyd's joke, but as I noted at the time, if the Standards and Practices folks (the networks' supervisors of legal and moral issues) raised a red flag, the writers would simply point to the standard dictionary definition (which might have had some sexual innuendo in that an unwholesome woman might also have unwholesome impulses in other directions -- but this was strictly a matter of inference).
Which brings us to the "Slutwalks" of late, which are more of an excuse for silly women to parade around in their underwear, imagining that they are making some profound statement or other. Janet Street Porter comments on the incongruity of it all:
Why are women so keen to appropriate the word slut? It’s a mystery to me. Slut, as Germaine Greer pointed out the other day, historically means ‘a woman of dirty, slovenly, or untidy habits or appearance, a foul slattern’ — nothing to do with sex and everything to do with cleanliness.
Maybe they've hit upon it unconsciously:
This is just a guess on my part, but I'll bet a substantial number of them are unacquainted with the finer points of personal hygiene; let alone the business end of a dishrag.
(* In retrospect, I was stoned much of the time, which even made their typically interminable beating-a-joke-to-death routines tolerable.)