"So he's a musical parasite. BFD."
I know nothing about Kanye, but it's SOP in the hip hop production milieu to sample music. It's tied in with the art of DJ'ing. Early hip hop DJ's/producers used to sample Kraftwerk's "Numbers" and "Tour de France", among others.
Which makes the form itself basically parasitic. 'Way back (in the 1980s), when I first started hearing rap it was basically poetry recitation with minimal (mostly rhythm) music underneath. It hadn't yet become violent, thuggish and crude, and although not my favourite I had a rap station programmed on my car radio. Whatever else may have been said of those early rappers, they were recording original work.