Permit me to say first that I have read Mann in English and in German — in German when I studied German and before I began to find German prose more and more difficult.
I personally, on rereading Mann, like him less and less, and this has nothing to do with the German language. Once a fan of The Magic Mountain I reread it recently and found it dull and uninspiring, but with value.
But what I really want to say is this: In 1914 Mann and the majority of German intellectuals, professors, and cultured elites believed Germany had been less than well respected in the West and had every right to seek more European territory. They supported the German war effort for the duration of the war; this included famous scientists and even Sigmund Freud.