The original author was a journalist (Gaston Leroux) who stood up for the demonised outsider and his novel was considered, what we now call, "woke" at the time. It contained an outsider, a poc and a strong heroine.

The story was a warning on how the trauma of othering and abuse someone to the point they are completely broken and no longer see themselves as human can damage a person. (And the difference showing kindness and understanding ((like Christine did)) can bring.