That´s understandable. It´s more feasible to create deep stories if you have a prefixed character to build upon that giving options for multiple choices.
But if I´m going to be an spectator or a passenger in the journey of a character some guy imposed to me, I prefer a book or a movie, not a RPG. If possible, If I´m playing a D&D adventure I want to play my character, not someone else´s, no matter how deep or well written the character is.