1. Length and Complexity: The manuscript was quite long (around 90,000 words) for a children's book, and the plot was complex, with many characters and storylines. Some publishers might have been hesitant about the length and difficulty for the intended audience.
2. Genre and Concept: Fantasy was not as popular a genre for children's books at the time, especially with such a focus on magic and a school setting. Publishers might have considered it too niche or too similar to existing works.
3. Young Author: Rowling was an unknown and unpublished author at the time. Publishing houses often prefer authors with a track record of success.
4. Market Saturation: The children's book market was already quite competitive, and publishers might have been cautious about taking on a new author, particularly one with such a unique and ambitious project.
5. Lack of Understanding: Some critics suggest that publishers simply failed to grasp the potential of the story. They might have focused too much on the surface elements and missed the depth, humor, and heart that made the series so popular.
It's important to remember that publishing is a subjective process. What one publisher finds appealing, another might reject. In Rowling's case, she eventually found a publisher, Bloomsbury, who recognized the potential of her work and took a chance on a new author. The rest, as they say, is history.