Personally, I don't like the roles of crazy maniacs with thousands of traumas that become antiheroes (and, all vile acts are justified).
However, I agree with you that Joaquin manages to humanize his character, in a natural way, without justifying nothing makes an verdaera individual and social criticism.
Definitely a difficult line to walk between justification of wrongdoing and the antecedents that result in a lack of sympathy, compassion and empathy. I think putting a lense on it is useful for showing that our present day attitudes of psycopathy and/or sociopothy is largely symptomatic.