"the bottom line of the movie as admitted by Gibson so many times is that he took it from the pages of the Bible itself, what's there to argue about?"
She's wrong--there's plenty in the bible that needs to be put into context and argued about. The writers of the bible put the words down years after Christ died, when Jews were persecuting this newfangled sect called Christianity (Saul who turned into Paul was one of the worse of them), and they apparently rewrote the story to put less blame on the Romans and more on the Jews (one passage in Matthew actually has the Jews saying something like "his blood be on ours and our children's heads!").
The New Testament, some of it, really IS anti-Semitic, but given the context of the times, you can't blame them.
Problem is, literalists took a statement written a long time ago under conditions that no longer existed and use it as justification for serious anti-Semitic acts--the progroms where men, women and children are killed and their houses burned down.
The progrom in "Fiddler on the Roof" only gave you a taste, an appetizer of what it's like. It was far more awful in real life. And it happened to them for thousands of years.