Son there's alot of people who always felt this way including Nas' own brother and daughter. One of my young homies got IWW as his favorite and greatest hip hop album of all time. Alot of MCs feel this way too. Such as Fab, G Rap, Royce, Budden etc etc. It's not some new internet opinion.
I regularly listen to both but could never feel the same. I like to play albums front to back but I never really get hyped for IWW until “the set up” through “if I ruled the world”. Everything before was too drab. I always felt like “Illmatic” had more color and life to it. It definitely sounds like he had more fun making it. I got a LOT of friends who prefer IWW, I also have a lot that prefer Illmatic. I think people that like IWW may like it because it feels more serious.