Fortunately for us, Mister Dresden lives in an interesting world, and he has bills to pay. He also has friends and enemies, who complicate things for him.
But everything that happens to him, it's just a result of him acting like himself, and everyone else acting like themselves. It is their world, playing itself out, without the intervention of outside entities. If there was ever a case where Harry was stuck in a tight jam, and the author reached into the world to solve his problems for him (or the reverse, and the author reaches in to paint a monster in his path where there was none before), then we would all mark that as the point where the series had truly jumped the shark; nobody would care about what happens to him if we know there's a deus ex machina contriving things around him.
Players (and Game-Masters) can influence the game world, but only through the agency possessed by their characters (where background elements are a type of character that is controlled by the GM). That is the central tenet of what an RPG is - that we are all playing characters, and the decisions which we make as those characters matter because there's no omnipotent outsider surreptitiously warping reality around them.