I guess we'll have to agree to disagree on this one though. There just will never be an equivalency to me between someone who has the ability to craft their own music from scratch: that is write a melody, write the chords, write the lyrics, etc. and someone who has largely made a career out of rapping/talking over other people's music and modifying it in some way.
I'm unwilling to privilege any one form of pop-music creation over any other. How is sampling any less "real" than going over the same three chords over and over?
What is more legitimately difficult and impressive, of course, is classical composition, where you're engaging in more complex forms with development and all that; where you're writing down each and every note for each and every instrument. There are a few people working in "pop" music with those sorts of chops – Sufjan Stevens is the obvious example here, he's a legitimately serious musician and artist.
This post is an excellent demonstration of why a composition's value isn't derived from its technical complexity, but from its inspiration.