Luther thinking that persons should read the book for themselfs rather than have it read for them doesn’t seem so obviously lead to fractuation.
IMO it does, because 1) people’s innate judgment / different life experiences / contrarianism / etc. can lead them to disagree on interpretation. [Relevant xkcd] If your centralized authority is a person who can respond to events and questions, it’s obvious what the Pope says you should do about X, whereas if it’s a book that needs to be interpreted, people can more easily disagree about what the Bible says you should do about X.
Note also that a centralized authority both discourages rather than encourages that sort of disagreement and directs status-seeking to climbing the hierarchy instead of finding a thing to disagree on.
IMO it does, because 1) people’s innate judgment / different life experiences / contrarianism / etc. can lead them to disagree on interpretation. [Relevant xkcd] If your centralized authority is a person who can respond to events and questions, it’s obvious what the Pope says you should do about X, whereas if it’s a book that needs to be interpreted, people can more easily disagree about what the Bible says you should do about X.
Note also that a centralized authority both discourages rather than encourages that sort of disagreement and directs status-seeking to climbing the hierarchy instead of finding a thing to disagree on.