By nature Marketing is reactionary, it’s playing defense. The consumer is about to make a decision and they have the ball. It’s up to you to convince them to shoot in your direction. The problem is that you only respond to the move (or try to influence the move), but the fact remains that the decisions happens elsewhere.
So marketing is much closer to economics or meteorology, than hard science. You can come up with best practices and systems to respond as fast as possible, but the important part is not tactics, but being able to create the strategy.