The blame fo this is only of Gotti sr. Castellano wasnt popolare as boss but he know how stay in the shadow and make money,Gotti only with forcing all capos and soldiers to show respect in front of his club gave infos to the feds on people that never was recognized as Gambinos made men.
Plus his was ruined by mouth,he bad mouthing of everything even if is a skipper that let made him more money. Gravano listening gotti that was blaming him for everything,decided to flip.
Another mistake was to use his son as street boss and this made angry more soldiers that lost money because gotti jr wasnt good in the sitdown and in 1999 there was a rumor that someone would kill junior.
If Gotti would survive the cancer for sure the sicilians in the family would shelve him.