This is why the Bundesliga can be called a farmers' league, as only Bayern Munich has the focus and ambition to win trophies, while other teams focus on profit making through player sales and other means. It's boring but that's the situation we see every season. Besides focusing on profit, these teams also lack the financial resources to compete with Munich.
After Leverkusen surprise victory with Xabi, we'll see Munich dominance in the Bundesliga return.
As I understand it, the problems in the Bundesliga are based on regulation - there are some inadequate requirements for the distribution of club shares that prevent investors from owning and managing clubs. If this had not happened, the situation could have been like in the Premier League, although on the other hand there would have been more dirty money in the league. Everything has its pros and cons.