Lynda Carter nailed this perfectly, utterly, and forever as Wonder Woman in her 1970s show. Wonder Woman was no-nonsense, but never mean. She was always ready to help reform and not merely punish. Wonder Woman didn't get angry at you for being a bad guy; she was disappointed in you. Just as your mother would be.
Melissa Benoitte has brought a similar quality to Supergirl and it's been a welcome lamplight in the otherwise dark and gritty landscape of live-action superheroism in the modern era.
Is that sexism, because we want 'girls' to be sugar & spice? Is it just realism, because women tend to embrace situational ethics while men hew toward rule-based utilitarianism? Is is just men taking men-heroes too seriously, just as they do themselves? When did being an actual good guy start to seem too weak for people?