The expectations for men and women differ in Aztec society because the society was a male dominated society (paternalisms). The father the sons the men had the responsibility to hold the family and keep his family in order. The Father was the bread-maker of the family. As a warring state the Aztec had warriors and these warriors were usually males. Warriors held great esteem in their society and were greatly respected. Women on the other hand were housewives the ruler of the house chores and her children. They have to take care of the children and be the teacher.
More on the Gender Differences can be seen at: http://www.socyberty.com/Ethnicity/Gender-Differences-Aztec-Society.108842