People Who Think This Is Just Another Zombie Film
Miss the point.
This wasn't just a 'Look how cool those zombies are!' film. It was about humanity, specifically that of the little girl who was watching it slowly seep away from her father before the outbreak, her sadness and disappointment at the selfishness of the people on the train (save for a small few, like the expectant father and his pregnant wife, and the shambolic but kind homeless dude), and her growing sense of faith in her father as he finally displays the goodness she knows is in him.