1)Music to me, at its best, should contain a marriage of harmoney, melody, and rhythm. They have the rhythm componet going for them, but they often leave out, or disregard the importance of melody & harmoney.
2)As a guitarist it's often hard to listen to a musical genre where the guitar plays such an insignificant role, if any.
I do though enjoy the cross-pollination of rap into rock & pop music. Do you think it will ever find it's way into jazz ( imagine Lou Rawls breaking into a nice little rap over Misty )