Why Christians deny that Adolf Hitler was a Catholic?

When a Muslim say that Osama Bin Laden is not a true Muslim, all Christians go like "ohhh, yes he is, he is a great Muslim, thats how Muslims are!", and when Jews go like "the people who killed Jesus were bad people, they were not religious" you all go like "no no, the Talmud cusses Jesus Christ a lot", but when we say that Hitler was a Catholic, you deny it without an excuse like he really was not a Catholic, can I know why is that?