Back when he first blew up, if you were looking for minority (as in smaller, not racial/cultural) opinions and voices you had to go out of your way to seek them out. The public perception/reception of an artist was part of the whole music marketing infrastructure where the money/labels controlled the message. But now anything that comes out is guaranteed to have a good spread of Stans, Haters, Crazies, Thoughtful Opinionators chorusing in the comments.
In Eminem's case specifically, his albums have always had an intriguingly stark dichotomy between his white people songs and black people songs: he had the mainstream songs intended for mass consumption, lush with pop culture references sing-song hooks, and rhyme-schemed for accessibility. Then he had those songs that reflected his background as an underground emcee used to freestyling, battles, dense hyper-lyricism-as-end. This is the former:
You can argue Em's pop rhyming is still denser/"harder" than most, but it's really about the artist intent. At the turn of the century it would have been difficult to get a comprehensive sense of the response to this ethnocultural dichotomy in his music, though everyone was certainly aware of it. You could get it out of reviews from journalists that ponder such angles, but not direct from the masses. Without having a melange of multicultural friends with varying degrees of background and interest in hip hop it was all speculation as to whether "My Name Is" or "Without Me" was cheesy to the black dude who grew up with hip hop, vs. the white girl in college who loved it. That sort of thread. But now it's something you can track closely via the related niche blogs, and, as I see it, it sort of platforms the art/music/product as window into the thin-slicing mind.
um, in mercifully shorter terms: a song like this is made to provoke reactions; it's almost more of an art piece than his actual "serious" songs. But it's only now in 2009 that we have the ability to treat it as such, before all takeaways were tied to its ability to generate money.