Almost everybody I have met who defends rap has an argument like Trevor's:
"Just because the popular s--t is 98% unlistenable tripe produced by talentless ghetto trash, that doesn't mean that there isn't any actual talent involved."
"... doing simple monosyllabic rhymes like DMX does, I'll grant you, is pretty easy. But just listen to Blackalicious' Ego Sonic War Drums, and if you still hear simple robotic beats under simple rhymes, then you're just biased and no amount of convincing, on my part or otherwise, would change your mind."
Here's the proof.
Now I don't remember any music being proudly hailed as "98% crap" until the 80s. Not music that got released anyway. You could say maybe 30% in the 1940s - maybe 60% in the 70s, but even the worst music then still at least rhymed and had melodies, if not always inspired ones. They had the basic ingredients of music.
This 2% of rap that's great has to be hunted down by the underground musicologists today I guess. And then all the other rap lovers will totally disagree with what you hold up as the only good rap.
Here's more of Trevor's 2% of genius
"Rap is not pop, and if you call it that then stop"
- "Check The Rhyme" by A Tribe Called Quest
Here's some more brilliant lyrics:
A song about the "Motherf**N***" in the White House who will bring us all together. I didn't make this up.
More of the 2% from commenters.
And here is RAGE AGAINST THE EQUIPMENT rapping about how rebellious they are and telling you why you should love them.