BTW, you asked no questions.
You asserted the following two falsehoods:
(1) Catholics cannot excommunicate themselves.
They most certainly can.
(2) Hitler died a Roman Catholic.
He most certainly did not. At the time of his death he had been an excommunicant for at least 34 years and had not attended a Mass in 42 years.
Calling Hitler a Catholic is like calling Stalin an Orthodox Christian, or Trotsky an Orthodox Jew or Rudolf Hess a Lutheran.
All four had deliberately rejected and turned their backs on their parents' religion and embraced ideologies that were implacably opposed to their parents' religion.
You told two lies and you got called on them.
you were the one who was way out of line.
Assuming the same standards applied in Deutschland in the 1930s as applied here, my assertion must be taken as a question ~ namely, where's the evidence that Hitler was actually excommunicated? Or, was he simply dealt with the same way people like Ted Kennedy, John Kerry, and others of that sort are dealt with ~ kid gloves, and not even a tap on the fingers?
It's not like this isn't obvious to outsiders ~ and if our "assumptions" based on what we see are not consistent with what you claim to be church law, then what are we to think?
Look, my own church had a problem with a guy named Jim Jones who was an ordained minister. He ended up convincing his congregation to drink poisoned koolaid ~ hence the origin of that ideomatic expression. His behavior had gotten out of whack even when he still resided in Indianapolis, and they should have pulled his license at that time. However, "they" (meaning Disciples of Christ authorities) didn't, and ended up with egg on their face. They lost a substantial percentage of their members over that little piece of stupidity.
Still, Jim Jones is not a "smear" on DoC. Having Adolph Hitler as an unbidden member of your church is no smear on the Catholic church either.
In both cases, though, failure of church administrative/ecclesiastical authorities to take affirmative and public action to kick these jerks out certainly is blameworthy provided that such actions would have provided any benefit to the other members, and to humanity in general.