When so many strong teams are out after the group stage, there is nothing good in it. And such moments with an out just spoil the whole impression and reduce the level of the tournament. Although Germany is in bad shape and a Japanese victory was acceptable, a victory over Spain is very doubtful. Japan is not a bad team but they shouldn't be top of the group with Germany and Spain...
That's football for you, buddy. When a team is not consistently in peak form and consistently produces well, a smaller surprising team will easily beat them and eliminate them from the competition. Perhaps they were convinced that they would qualify from this stage because they were playing against two less competitive teams than them, but that is not football; the unexpected always happens and leaves people stunned. Hard luck, Germany, and hope they strive harder at the next World Cup.