Why words do this, how they do it, how to prevent them from doing it nobody knows. They do it without the writer’s will; often against his will. No writer presumably wishes to impose his own miserable character, his own private secrets and vices upon the reader. But has any writer, who is not a typewriter, succeeded in being wholly impersonal? Always, inevitably, we know them as well as their books.
This is a valid point. In any piece, the author always injects some form of their personality/morals/ideas into their writing. It isn't always on purpose, but the way the reader understands it develops an assumption about who the author is.