Why did Guy de Maupassant use an objective and dispassionate style when describing characters?

Guy de Maupassant adopted an objective and dispassionate style as part of his commitment to l’humble vérité (the humble truth), aiming to present the manifold aspects of life without imposing personal moral judgments on his characters.1

His approach was rooted in the principles of Naturalism, which sought to apply a scientifically analytic method to literature. By observing and recording the "little dramas" and daily preoccupations of ordinary people, he focused on capturing the specific words, gestures, or reticences that betrayed a character's essential personality.1

This technique allowed him to function as an observer who documented the deterministic relationship between a character and their social or physical environment. Rather than moralizing, he used a rigorous economy of language to reveal the hypocrisy, neuroses, and desires masked by everyday appearances, ultimately presenting his characters as victims of ironic necessity or fate.231