Well, actually, I don't even care that much that he leaves for Bayern. It makes sense with his whole family and many friends living there and all that. However, the way the move happened makes me really disappointed.
He could have made an easy exit last year. He failed as captain, Klopp left and everyone agreed that we need a new start. Bayern was miles away from us and while most people obviously wouldn't have liked to see him go to Bayern, it would have been okay after such a shitty season. Also, Hummels had two average seasons and we would have gotten a nice sum. He had great years with us and it was a good time to part, just like Klopp.
However, he stayed. Actually did good as captain, played constantly well again and Tuchel showed to be a great coach. We played a brilliant Bundesliga season (which could still become the best in club history) and minmized the gap to Bayern, all while having to cope with a difficult EL schedule. Leaving now just feels wrong and backstabbing. Even more so, when you look at the way he made it such a big topic just weeks before the cup final without a proper reason. That interview after the Hertha match, his dad's interviews, etc. Hummels very well knows what happened after the Götze announcement, this is just a big shock to the whole club and with that, he basically single-handedly killed the rest of our season. Who really doubts that Bayern will win the cup now? He should have just waited until after the cup final with that kind of shit. With Götze, you at least could still make the point he was young and Bayern put him under pressure with the "either now or never" stuff. With Hummels, there's no good excuse. It's sad because instead of being remembered as one of the most important players in the Klopp era, he'll just be remembered as the worst captain BVB ever had.