One should clarify that basically nobody tries to "predict" anything with Black Scholes, just as basically nobody "predicts" share prices by doing a discounted cash flow analysis. Yet, they each provide the conceptual framework for trading (of options and stocks, respectively) in such a way that those that have better predictive power make money, on average, at the expense of those traders that don't. With that, they make the market efficient for traders that trade for other reasons (hedging, investing, gambling, etc.).