Why do you think Karana burns the village instead of keeping some of the materials?

Karana wanted nothing from the village, as all it held for her was memories.

I sat for a long time, seeing these shapes and hearing the voices, until the sun came out and the fog vanished. Then I made a
fire against the wall of the house. When it was burned to the earth I started a fire in another house. Thus, one by one, I
destroyed them all so that there were only ashes left to mark the village of Ghalas-at.