Muted Group Theory is a critical theory because it is concerned with power and how it is used against people. While critical theories can separate the powerful and the powerless any number of ways, this theory chooses to bifurcate the power spectrum into men and women. Muted Group Theory begins with the premise that language is culture bound, and because men have more power than women, men have more influence over the language, resulting in language with a male-bias.
Men create the words and meaning for the culture, allowing expression of their ideas.
Women, on the other hand, are left out of this meaning creation and left without a means to express that which is unique to them. That leaves women as a muted group. Those different experiences are a result of men and women performing different tasks in society. Men enact their power politically, perpetuating their power and suppressing women's ideas and meanings from gaining public acceptance. Women must convert their unique ideas, experiences, and meanings into male language in order to be heard.