A book is knowledge, knowledge can 100% be a family businesss to be continued. I don't see it as any different from a family restaurant protecting their recipes in an otherwise cutthroat industry.
The terms is too long as is, but I see no reason to not have any posthumous transfer period so the family can figure out what they want to do with their knowledge.
People have a secret but still share it while withholding some knowledge. They risk someone reverse engineering it, but it's still being monetized.
Whats the difference here? Have idea, share some of it, monetize it from peope who want to use it, later on it's a free for all or enough knowledge comes to easily reverse engineer it anyway.
^Just because an artist releases a work to the world, doesn't mean they have any natural rights to own what the culture does with it.
No natural right, no. But humans are greedy, tragedy of the commons, etc. So governments made copyright to protect those artists.
It's been, as usual, perverted by the people who least need that protection, but the idea is still sound. In a world of greed, give the creators time to be greedy so they can make a living off their own work. Then later on its a free for all.
Aside from the flaws in your analogy already pointed out to you, there is actually very little value in a secret recipe. A skilled cook will be able to reproduce something close enough just by seeing and tasting the result. The real value of a family restaurant is the pride in their legacy that gets them to actually stick to a recipe that gets that result instead of cutting corners in order to maximize profit.
The terms is too long as is, but I see no reason to not have any posthumous transfer period so the family can figure out what they want to do with their knowledge.