It's the same reason the Arabs hate the Jews so much, they're terrified of them. There's somethig about the Jews that sets them apart. The Arabs alternate between being jealous and scared of the Jews. They remember the 6 day war.
That dividing line is spiritual. Anyone who expresses an irrational amount of antisemitism is smitten with that same spirit of jealousy, hatred and fear.
There's really no other explanation.