Well, they do serve a purpose.
Next time someone accuses Gibson -- or anyone else in a similar context -- of antisemitism, because of his (or the Gospels') portrayal of the Pharisees in a bad light, simply show them what these turkeys are all about, and then tell them that this is the type person he's talking about. Whether the "Phariees" in question are Jew or Gentile is immaterial. It's what they do, not who they are.
These guys fulfil the "blind lead the blind and they both fall in the ditch" imagery to a "T".