Dortmund's main goal is to make players. Dortmund builds on the experience of young players, and earns money by selling them. They can make players. Other teams benefit from having these experienced players on the team, while Dortmund can make money. But as a result, the Bundesliga has become completely controlled by Bayern Munich. We don't see any other team win the title except Bayern Munich. I think this will reduce the value of the Bundesliga, they will lose the audience.
Yes I also see that is the goal of Borussia Dortmund in establishing a "business" in football. But they have always had success with it. I hope, if they focus more on achieving achievements in the future I think they will be able to do it. Moreover, they will be more cost efficient because they are able to create young players without having to buy them from other clubs. It would double their profits if they actually did.