In the NBA, the superstar player has so much leverage and power over what happens with his own future. Superstars are catered to and decisions are made with them as the corner stone. Management wants to please them as much as possible. And players can’t be just cut from the team. Well, they can get waived, but that only happens when end of bench players and it’s always a money decision to free up a roster spot.
Meanwhile in the NFL, superstar players are important for the franchise, but the franchise itself is the driving force. It’s not the player running the show, like you see in the NBA. Most people who watch the NFL support teams. You do have some bandwagon fans who follow specific players, but the majority just support their local team. And players sometimes get cut mid-season when things are working out. That’s something you’ll never see in the NBA.