Nas felt that way because of the way he felt Marley was moving. He wasn’t feeling the business side of shyt and how his music would be leaking and random nikkas would be on his shyt. It’s prolly best for Nas’ career that he stopped letting Marley Executive Produce it.
To quote something from King's Disease, Nas' relationship with Stoute wasn't 'all bad'.
Hanging with Marley: Firm might've stayed intact, IWW would've been more street/Queens focused.
Hanging with Stoute: hooked up with Trackmasters, hooked up with Lauryn Hill, hooked up with Will Smith --> These were KEY to Nas really blowing up. He's talked about this a lot but Illmatic did almost nothing for him personally. It got him acclaim but he was basically surviving through features and advances. It was IWW and his moves that secured him financially, pretty much for the rest of his life (up until his investments started popping off). And let's not forget - IWW is a classic album in it's own self. It proved that Nas was versatile ("One of the most creative LPs ever to hit stores") and couldn't be pigeonholed even though critics have tried to do this ever since.
Even Cormega has said that in hindsight he understands the moves Nas had to make. Without Stoute Nas might've been on Buckshot/Smoothe Da Hustler(or Cormega) levels, and that's no diss those are my favorite rappers but it is what it is. SHYHEIM dropped on the same day as Illmatic did and moved similar amounts of units in that year (not in the first weeks, Illmatic definitely had a bigger buzz, Illmatic didn't start selling again until IWW/Stillmatic bumps), but Shy got that Wu bump. ON & ON was a more succesful single than any of Nas' singles. Put that in perspective.