Cause hes viewed as an Old Head and hes actually Jay Z age, and he could remember Nas coming to his studio on some "lil dude from Queens that wants to rap just like me" style and then Nas over the years not only lapped him, but became the Messiah of lyrical East Coast Rap and purist Hip Hop culture in general, while he kinda fell off and never really got back to that when that shouldve been HIS throne, even with Dr. Dre in his corner. And now hes arranging a literal award ceremony to give him 500k and free healthcare. Nas kinda sonned his own idol. Why else would he get mad about a dope tribute song about him for years? UBR was the "reason" for their original fallout