Dortmund's handing over the title to Bayern Munich shockingly on the final match week was unbelievable to me as well. However I don't think Dortmund board are mad at this situation too much. I mean Terzic wouldn't get sacked for this. Because Dortmund's main target in this season was never to win the Bundesliga title. Maybe they got too close to doing it thanks to Bayern Munich's making many mistakes. But this was going to be extra effort by Dortmund if they made it.
I believe they met the expectations for this season as usual. Terzic's management would be appreciated due to staying in the title race until the final moments as well. Now the board must be aiming to make as much profit as they can from Bellingham's transfer to Real Madrid. This is their main vision of team management in the end.
This was just similar to Manchester City and Arsenal in the EPL, from my observation Dortmund were determined and had a chance with talents and hard work but Bayern Munich had enough experience on winning titles especially the league title and they have proven that again this season as they snatched the title from Dortmund at the last minute.
I would say Dortmund's performance was similar to previous seasons. I don't think they played very well. However, Bayern Munich's performances this season have been erratic. And this is why the Union was able to occupy the top spot in the table with the likes of Berlin and Dortmund. If Dortmund played well in the last match, they could have won the title. The team lost the title due to their stupidity and erratic performance. And I don't think they will be able to break Munich's dominance for the next few seasons.