A Question Regarding Voodoo

So, this struck me late last night, as I began another novel, published by a Christian publishing house.

Why are Christian novelists into writing about voodoo? I mean really? We need to read about this? Even from a "Christian" perspective?

This is at least the third or fourth novel I've encountered in the last while that has the main character interacting with voodoo, and someone who wants to put a curse on them. It's for certain at least the second one in my personal library that touches on the topic.

Is there really that great a demand for this?

(I'm not certain I'm going to carry on with reading this particular novel. I bought it because it is a part of a series I've greatly enjoyed, but with the way I'm sensitive to stuff like this, and the way I get nightmares, I'm not sure it's the best plan on earth for me to keep reading this.)