What would cause that lousy treatment?
Anti-semitism. The Catholic Church was guilty of it, Protestants were guilty of it, Muslims were guilty of it.
Blood libel, the blaming of Jews for the death of the Son of God.
Lots of ignorant knuckle-draggers still harbor their Jew hatred, and they do it in the name of some god that they worship.
Very well put. Unfortunately, some of the Jew-haters are lurking on this site!