I need to preface this review by pointing out that I've never really been into rap or hip-hop. Once upon a time I thought Eminem was kinda funny, and there was this mashup of Tupac's "Starin' Through My Rear View" and Phil Collin's "In the Air Tonight" that I downloaded once off of Napster or Kazaak a long time ago. And I guess you can count some Gorillaz tracks as hip-hop thanks to Del the Funky Homosapien.
Otherwise, the genre has been mostly impenetrable to me, partially because I like to sing along to music, and rap isn't exactly singalong stuff in my experience. The other problem is generally the subject matter: I'm not going to suggest that it's the case for all or even most rap, but much of what I've heard on the radio is about sex, drugs, violence, drinking, partying, and other things that generally don't interest me as musical subject matter. As a result, I've never spent much time listening to the genre.
That said, Tupac's "Starin' Through My Rear View" gave me a glimpse of something else rap music could do, though I never followed up on it: it gave someone from a very different life than my own a chance to explain what their life is like. It's not just beats and words; it's a story, or a perspective. And if you can tell that story or give that perspective in a compelling way, then you've made compelling art. It's poetry.
"College Dropout," I contend, is compelling poetry.