Why do Wiccans and Pagans insist Hekate is a Maiden-Mother-Crone Goddess when she clearly isn't?

'Maiden Mother Crone' is a modern thing; it did not exist in ancient Greece; and Hekate was more often described as Maiden, so what is his "Crone" nonsense about people? Robert Graves was possibly the first to depict her this way but historical depiction's of her are of three young maidens.