I don't really understand the business but if a child is not taught to do business before being trusted to manage it then the business that is run will not necessarily be successful.
He is not interested in the business left by his father and it is certain that he will not be so interesting to develop it.
We also need to know his educational background so that we can have more information that we can discuss, it would be good for every parent to teach education in running a business so that when he is gone the child will be much easier to develop.
Expertise will determine the level of success of the business left by his father and if his ability is not there then it is impossible for the business to grow much more because there will be competitors who try to beat his business to become less developed.
I agree with that, we should not just focus on continuing the business that is already running because if we do not have the skills then it is very possible that the business will collapse even though it used to dominate the market share, I say this because I have experienced it in my extended family and the ones who should be blamed are the parents who do not teach their children from an early age to prepare them for the business that they have built.