Our inner mother takes over with trying to get rid of the pain because of how uncomfortable truth being communicated from our inner world feels.
If we make her a virgin mother, we don’t have to glorify feminine sexuality... So as a collective, we go along with the only acceptable Feminine archetype.
We can find the Dark Mother in Goddess-worshiping traditions. Kali, Hindu Goddess of creation, destruction and shadow, is often depicted with dark skin.