That would make perfect sense, if a story were a living thing with a will of its own. It isn't, it is a creation wholly and totally shaped from conception to completion by the author. That author IS that authority who decides its meaning, they decided it at every level and step it its creation. Now sure there are plenty of authors who refuse to provide any intent other then the stated words and at that point we do just have to guess. But so long as they provide some kind of intent that intent is the true one.