Singers who can't sing....I've been saying this for years

Okay, so I was at Spirit West Coast once, and granted, it was the smaller stage and during the day, but I see this guy who is an amazing rapper, almost on par with Eminem, and then he starts this song where he actually has to sing, and no lie, he didn't hit even one note right during the entire song. It was excruciatingly painful to watch, but didn't stop the guy from doing it. I think this article finally explains what I've always wondered about.

http://new.music.yahoo.com/blogs/getback/53773;_ylt=Arg23iUlN5GbUvN685tS514exCUv