She demands equality in male-dominated professions because experience has taught her that male dominance exists only because women are denied opportunity.
Elizabeth Cady Stanton begun with finding her housework mundane and depressing and started sympathizing with other women who had not had any access to power and privilege.
She theorized and reasoned that all assumptions about women being less intelligent and capable could not be true because women haven't had the opportunity to test and show their intelligence and skills. She continued on to advocate for women's rights and laid down the foundations of feminism: liberal feminism, cultural feminism and dominance feminism.