As he should be against the aliens...but his desire for humanity makes for a compelling story as he fights to destroy the alien invaders while only wanting a peaceful “human” life.
Layer on the metaphors of modern World soldiers who fight in battle but truly only want peace, and it becomes an engaging story.
A robot that wants to be human juxtaposed against human warriors that are forced to become machines to survive battle. Both are desiring the opposite of what circumstance has forced on them.
Yet, they must both find balance to survive...and salvage happiness when it is over.