What is Dickenson's purpose in writing her poem, "I'm Nobody"?

Whenever I read this poem, I cannot escape the fact that Dickinson seems to be making a strong indictment about those groups of people who are deemed "popular" and "accepted" by the social forces.  Being a teacher, I cannot help to identify the poem with the social forces that seem to dominate adolescence.  While this might not have been the direct purpose in her writing, one can see much in the way of parallels in both.  There is a social setting that determines popularity and the valence of being accepted.  At the same time, there are those who do not "fit" this mold and are isolated.  As they are silenced voices, their expression is not as valued as others.  Dickinson's purpose that is to assert voice for those who are voiceless.  In the first stanza, she seeks to bring community between two who have been deemed as "rejects."  This would be why she appropriates the term, "Nobody" in a powerful light, one of solidarity, as opposed to isolation.  In the second stanza, armed with her newly established community setting, Dickinson is able to articulate how terrible it might be to be deemed as "popular" and "accepted" because of the lacking of individual character and diversity.  In the final analysis, Dickinson has taken something that would have been seen as a stain and wears it as a badge of distinction and worthy of a rallying cry.