Dortmund are the engineers of their own downfall. I can remember those years when Dortmund were the only team giving Bayern Munich tough competition each season but those glory days are slowly disappearing because Dortmund turned their priority to be a business oriented club and selling out every top talent they get for huge profits not minding the competition ahead of them. Leverkusen have now stepped up to become the contender for Bayern Munich. They are focused on competing and winning trophies.
Yes you are right Borussia Dortmund used to be great team but now they are not doing well because they care more about making money than winning games. They used to challenge Bayern Munich but now they sell their best players for a lot of money and do not think about how it will affect their team. This has made them weaker and now Bayer Leverkusen is strong competitor to Bayern Munich. Leverkusen wants to win trophies and be the best and that is why they are doing well. Dortmund needs to think about what is important again if they want to be top team. They made a mistake by focusing on money instead of winning and now they need to change.