Have the Germans always prevented civilization from progressing in Europe ?

That is what Nietzsche was suggesting. The Renaissance was thwarted by Luther, as wars in the name of religion prevented Europe from coming to terms with its christian heritage. Kant prevented the blooming of the Enlightenment by imposing metaphysical abolute truth in the name of Reason. As for Hitler or Kaiser Wilhelm before him, they brought havoc and questionned the very abilty of Europe to grow any civilization (Nietzsche could not witness either of the two world wars).