ethno etiologies

Many cultures have ethno-etiologies that provide explanations for illness that are not based in science. From a biomedical perspective, the non-scientific medical treatments provided in these cultures have a low likelihood of success. Despite this, people tend to believe that the treatments are working.

Why do you think people tend to be satisfied with the effectiveness of the treatments they receive that are based on the ethno-etiologies? 
In transcultural nursing practice, why would it be important for nurses to understand such ethno-etiologies when nurses interact with patients of different cultures?