I definitely think that (America, at least) likes to pretend that it’s one big happy society. Like when they papered over the cracks with the Missouri Compromise, and then that got messed up by California obtaining statehood, and then there was the Kansas-Arkansas Act…sorry, history geek. Point is, it’s definitely terrible to simply point out just the good or the bad stories, and really marginalizing. Have you read this post? http://resistracism.wordpress.com/2010/08/27/we-are-human/
When people retell stories of marginalized people, they choose one of two routes, generally. Either they turn this person into an inspiration (like a person who’s not common-bodied completing a marathon) or they tell a tale of woe that pulls at your heartstrings and fascinates you. The first is marginalizing for a couple of reasons: reducing the person’s existence to this one/these many accomplishments & their marginalized status, implying that whatever was done could not ordinarily be done by people of their status (which is condescending), and implying that all people of their status should be able to do it (which is victim-blaming). The second is marginalizing because: it reduces the person to their horrifying experience(s) & status, it’s done for entertainment usually- people can shut off the PC/TV and go back to their privileged lives, and it just…makes them inhuman, simply characters on a screen.