I believe their original characters and worlds aren't good for obtaining money.
Youch! I'm an aspiring author. I don't ever intend to make money on my Zelda Classic quests, but some of my quest content is loosely based on books that I do intend to profit from. Our characters may not be widely known at the moment, but neither was Harry Potter at one point. You've got to start somewhere, and it's all about gaining the attention of a wider audience through good storytelling.
Edit: Edited this a bit because I took too much offense by misinterpreting these words. Sorry about that.