On the other hand he was praised for his work by players like Kimmich and Muller. His tactical detail and preperation were specifically highlighted as very strong points. He can adapt systems and that is also a big plus for me. For me, Nagelsmann seems to have some specific qualities that are perfect for working on the areas that we have been lacking the most for quite some time. It would be nice to finally have a tactically sound manager who is also hailed for his high-intensity and tactical training methods.
Nagelsmann managed an average of 2,31 points per game at Bayern and was followed up by Tuchel, who only got to 1,95 points per game. As reference: Guardiola averaged 2,41 at Bayern.
Obviously Nagelsmann was fired when losing 1st place in the Bundesliga on matchday 25, also with some rumours that there were troubles with players, which was debunked by Kimmich after he was fired.
I can imagine some Bayern fans not being that impressed at they thought they would have secured a long term manager with the German wonderkid manager Nagelsmann, but in my opinion you can't say he failed hard at Bayern.
Van Gaal was far worse at Bayern than Nagelsmann and we also signed van Gaal, so I say we get over some disappointed Bayern fans and get Nagelsmann in the summer.