The model of strong female character as lone warrior seems to have rather a lot of connections to the US model of individualism at all costs and the belief that everyone should pull themselves up by their bootstraps. There’s a common attitude in the US that interdependence is a sign of weakness; it’s telling that functional relationships in which people help each other and each have something to offer are often framed specifically as ‘dependent,’ rather than ‘interdependent,’ with a sneer reserved for the person who needs assistance. In US culture, you are failing if you need help, whether from friends, family, or the government.