Seriously, How DID Cryptozoological Erotica Become BIG?

I just read an article on Time Magazine's news feed titled How to Make $30,000 a Month Writing Bigfoot Sex Scenes by Kate Knibbs. In her article, Ms. Knibbs writes the following:

Writers, especially self-publishing beginner authors, aren’t exactly known for making money. But perhaps all the would-be Franzens are barking up the wrong genre. There is a proven way for unsigned writers to make $30,000 a month, according to The Daily Beast.

Digital cryptozoological erotica. Otherwise known as monster porn e-books.

Wade, the woman behind the Moan for Bigfoot series (there are 16 installments) makes thousands every month selling these bizarrely appealing e-books through Amazon’s Kindle Direct Publishing. Wade (which is, unsurprisingly, a pen name) may retire from the genre, though, after Amazon’s decision to tighten restrictions.

Okay, cryptozoological erotica (aka monster porn), sounds bizarre to me. I'm not interested in reading about bigfoot having sex with another species, thank you very much.

However, there is obviously a market/high demand for monster porn if authors are making $30,000 a month writing these types of books and short stories. I guess it shouldn't be too surprising as sex sells... But, for monster porn, really?? I find the entire notion of the monster porn genre creepy myself. What are your thoughts about cryptozoological erotica (aka monster porn)?