Historically “witch” was for malevolent magic users.
But the word has developed different meanings now. This is the case for many words. Dandy, Gnarly, Gay, Slut, and so on. Slut used to be a messy person. Gnarly was just a knotty piece of wood, Gay meant happy, Dandy meant flamer. It goes on and on. Witch has a partially positive meaning now and lots of people want to jump on the bandwagon with it and why not? Its an exciting empowering spiritual approach for people who are on the fringe.