What is it that makes a Dalek what it is? How much is nature and how much programming?
Is a Dalek’s loathing of all other lifeforms an intrinsic part of it from the moment of creation or a matter of meticulous indoctrination? Would a Dalek that had never had any contact with another of its kind still be the lethal xenophobic killing machine that its brethren were, or could it be peaceful, open-minded, even friendly?
That’s a question unlikely to ever be answered.
Daleks are hatred personified; it’s all they know. Purification of the entire universe is their only goal.