Why does Juana follow Kino's life path even if she disagrees with some of his choices?

Juana realizes the change in her husband from a normal man to one with a questionable grip on sanity. It is ironic that, when Kino declares that he is a man, he begins to act "half insane and half god," thus negating the qualities that define him as a man. Juana is, in the end, subservient to Kino because her culture and belief systems are intrenched in the idea of male dominance even though she knows better.