Because so many Christians are decent people.
The Jews were the target of Hitler's hate campaign.
True Christians do not hate Jews. Nominal Christians may hate them because they are a different religion.
It would be difficult to say exactly how many hated Hitler, but it would probably be millions.
The majority of Christians, not just Catholics did hate Adolf Hitler, you're correct. They did not endorse the genocide of millions of people because of their religion, and Christians believe that no one should be punished because of offenses of their ancestors. In short, the Jews in the 1940's had nothing to do with Christ's death, and should not be punished for it.
Hitler planned on killing all of the Jews.
He hated them stupid jews!!!!!!!!
maybe
Who or what was there to stop him?
Hitler
Because Hitler blaimed the Jews for the tragety of World war I.
Hitler absoluetly hated the Jews, and tried to exterminate them, by gassing and brutally killing them.
Hitler was the one mainly responsible for the killing of the Jews, but he was not the sole responsibility as all the people who supported him and carried out the killing tasks Hitler set them also shares some of the responsibility.