The entire story was spoiled to the internet after the first voyage. Why do I, a Star Wars fan, need to spend the $4.7k to stay on the ship when I already know the story from every angle, virtually explored the room, seen the ending (the outcome seems to be set), and the merch?? I am not going to pay $4.7k to taste the food.
The entire experience is cataloged online. From a fan perspective, you don't need to really go on the Star Cruiser to experience what happened. I also think of all those fans that are socially awkward or do not want to participate - why would they want to do this? I mean, maybe if voyages are only half full... but still.
Unless Disney can write a new, fresh story and prevent it from leaking, I don't know why any fan would need to pay that price.