If your talking about making into a movie, It's so people could see it how stephanie saw it. Her view became your view. 読書 the book あなた could imagine many things for Bella but in the movie あなた see the only face for Bella, Edward, Emmett, etc. Also because the 本 were a hit then why wouldn't the 映画 be a hit? People would make a lot of money and those playing the main characters would be known world wide. If your talking about the book it's a simple answer. See Stephanie had a dream which made her sit down and right it. She got engrossed with it and ended up making a whole saga. I mean it can happen. Plus 書く is a passion to her. Maybe she just wanted to make a new era a ヴァンパイア to.
