I wish I could remember (panel 2 lol) but there was a fairly comprehensive analysis of literary tropes in European folklore that put forth that the reason the "hag" was demonized is that it is a woman who is unable to provide the patriarchal definition of worth: childbirth, domestic duties, sex. To the same degree as younger women and is also a source of advice/wisdom that could fly in the face of said patriarchal definitions.
To answer the question though, literally me.