“When the gentiles all around heard that the altar had been rebuilt and the sanctuary dedicated as it was before, they became very angry. They determined to destroy the descendants of Jacob who lived among them. So they began to kill and destroy them among the people.”
There is no indication why the gentiles around Israel were angry about the rebuilt altar and sanctuary. However, they seem to be. Notice it is the descendents of Jacob and not Israel who are the object to this dislike. These gentiles then turned on the Jews who lived in their countries as they begin to kill and destroy them.