In your study of The Craft and the various aspects of the Goddess, you learn that some of the Goddesses from ancient times are "dark goddesses." For example:
Baba Yaga, a Slavonic goddess, is described as a tall, gaunt hag with disheveled hair who lives in the Black Void.
Ama is a dark goddess of death, "the dark, sterile mother."
Unu - from her flows all discord.
Kali aka Kali Ma - a hideous demon goddess who wears a necklace made of human skulls. Two of her teeth are like tusks. She wears two small children as earrings. She battled Raktavija, a demon, and after she killed him she drank his blood. Then she danced so violently that the earth shook. When Shiva tried to calm her down, she killed him too. Usually she is depicted standing on Shiva's dead body.
Tiamat, the "chaos dragon."
Lilith, the "night-hag of the Hebrews." She kills newborn infants.
Coatlicue, "the devouring goddess of Aztec nightmare." Her skirt is made of snakes; her hands end in sharp claws; she wears a necklace made of human hearts that she has torn from her victims.
Black Annis, a Greek goddess who eats children and hangs their skins up to dry.
Ereshkigal is the "queen of the underworld" and "the mistress of death."
Bhavani's eyes and tongue protrude horribly; she wears a necklace of human skulls.
Hecate has three heads, and her hair is made of snakes; she dines on excrement; and she roams the earth with two red-eyed hell-hounds.
Question: Why would anyone want to connect with such deities? Where is the attraction?
I believe that ancient peoples saw death every day. Their life expectancy was short. Wars and plagues brought death on a massive scale. Just as life and love were attributed to the Goddess, death must also be attributed to her (or to some aspect of her).
"Assigning" this destruction to a goddess was a way of dealing with it. Just as there were goddesses who presided over conception and birth and life, so were there goddesses who represented The Dark Side.
And when ancient peoples acknowledged such goddesses, they were as much as saying: "I will face you unflinchingly. You are my annihilation, but I will make peace with you and will not fear you. Death is a part of life, a necessary aspect of the cycle of nature, and death must come in order to have rebirth. Death is not the end."
And the Dark Goddess can be an ally. She can be a fierce protectress. There are times when you need to be nurtured, and there are other times when you have to be a warrior. The Dark Goddess comes to our aid when we have to "throw the switch" and fight for our lives (a time when it's to one's advantage to "go postal") or fight to protect someone who is weak and helpless.