Pacelli Germany over to Hitler with the demise of the Catholic Center party and the Enabling Act.
Had Pacelli not read "Mein Kampf?" Did not his "faithful companion" and Bavarian German nun and assistant for 40 years not translate Hitler's clear intentions to him?
That enclyclical did nothing to curtail Hitler. All it did was to cushion the Roman Catholic schools and churches in Italy.
And a declared excommunication would have had no more positive impacts—the point had already been made.
Of course, Pacelli had read Mein Kampf—how else would he had counselled Pius XI to write the encyclical to which I linked in post 50—but I don’t suppose you read that either.
??? Mit Brennender Sorge had nothing to do with Italy, wasn't directed to the Italian church, was written in German, not Italian, etc.
You might as well say that it contained a good recipe for fettucini alfredo; that would make as much sense.
Why was Hitler not [formally, by decree, by name, as an individual] excommunicated, while Luther was? Easy: Luther was a theologian, was a churchman, and was a priest.
Hitler was none of those things. He wasn't a practicing Catholic at all after 1918. (Posting a picture of him leaving a Protestant church after giving a campaign speech doesn't prove he's a practicing Catholic, sorry.)
And, as you have been reminded -- is it maybe a hundred times by now? -- Hitler was excommunicated latae sententiae (automatically), many hundreds of times over. Every time one of his minions, on his orders, beat up, tortured, or killed another Catholic priest or religious, that's an excommunicable offense.