What if the problem is the assumption that problems can be solved with rigid rules, universally applied without consideration of context? What if the problem is the assumption that rules make something objective?

There's no universal definition of "asshole". That's okay; you can still have "Don't be an asshole" as a rule, because the interpretation of rules is inherently a subjective act. You can either subjectively interpret this rule, or you can subjectively interpret a convoluted system of rules designed to exclude assholes in an "objective" way, and fail at both excluding assholes AND being objective.