Why did the Nazis hate and hurt the jewish people?

Answer 1

The German towns people said they did not know about the killings. The Nazis leaders said the Jews had to be eradicated. The grunts of the Wehrmacht and SS said we were "just following orders". They had no remorse and were rather proud of themselves. It is bad enough the military people did not care, but it is worse that the German populous did not cry, did not beg God for forgiveness or care about the Jews.

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The Nazi leadership and Nazi Propaganda claimed that the Jews:

1. Were fundamentally alien infiltrators in Germany
2. Had caused Germany to lose World War 1
3. Were (for the most part) Communists
4. Were trying to dominate the world
5. Were undermining morals in Germany

Please see the related question for more detail.

Answer 2

It's complicated, but basically the Nazis didn't have a monopoly on this; they took it a bit further than most, but it was really a riff on a general theme. Jews are by custom and their own religious laws a people "set apart", which means they don't necessarily assimilate easily into other cultures and also makes them more readily identifiable.

Germany after WWI, and particularly in the 1930s, was a pretty miserable place. The Treaty of Versailles was extraordinarily one-sided and punitive, and while Europe in general was impacted by the Great Depression, Germans had it rather worse. There was, in addition to the general suffering, a perception that a small group of people, many of them Jews, had "sold out" the Germans at the end of WWI and forced the signing of an onerous treaty. So it was easy for Germans to blame Jews for at least a portion of the hardships they were undergoing, and from there it wasn't terribly difficult to blame them for all of it.

The Nazis actively encouraged this, and used the Jews as a scapegoat for everything that was wrong with Germany.