The diminishing compassion for Madame Schacter hints towards what theme?

As the crowded train full of Jewish prisoners makes its way to Auschwitz, Madame Schachter starts going out of her mind. With her disturbed mind tortured by apocalyptic visions of hell, she constantly screams, terrifying and unnerving the other prisoners. Far from being compassionate towards her plight, everyone is becoming increasingly unsympathetic. Some people even physically assault Madame Schachter in a desperate attempt to stop her blood-curdling screams, but all to no avail.
What this tragic episode illustrates is how the Jews of Sighet have been stripped of all their dignity as human beings. Treated like animals by their Nazi captors, the prisoners have been forced to engage in a brutal struggle for survival in which basic human empathy and compassion have no place. And this struggle will only get more desperate, more intense, when the Jews of Sighet finally reach their destination.