The truth is, 50 had no business putting ANYONE in the "Step your rap game" section when he hasn't had a good quotable since his pre-GRODT days...and even then, he was never a great lyricist...
You also got to remember that MTV was comparing Joe to 50 as the next big thing. They both came from the same place( mixtapes) 50 is not going to let anyone else get any kind of shine. So of course he put him in the step your game up section. Hell If joe would have sold alot more with his debut album, I really think 50 would have came out and dissed him( instead of just dissing him at shows and ect)