I have always been amused to be here....simply an awesome post..
There also seems to be quite a bit of stereotyping when girls are the main characters in picture books. I've heard librarians say that girls will read books about boys, yet boys won't read the books about girls. I'm not sure if there are stats about that, but it seems it has developed into swaying purchasing decisions. In my experience, boys will read books about girls--especially popular books like The Hunger Games and on the picture book level, Olivia.
And there are so many seemingly gender specific choices in the early reader section, too!