As it was apparently a successful business I guess that's quite an incentive - wonder if Sheila was annoyed about that deal 
Sheila got $10,000 pounds right off the top for doing nothing. He would only make money if he put in the hard work to keep it a successful operation. If he did a crappy job and it loses money then he doesn't make anything.
That is the way things were when the family was alive as well and why Jeremy was annoyed. He had to work for the business in order to be provided a place to live, car and salary. Sheila was provided with a place to live and money without any need to work for it.
If you like the family business and don't mind hard work then you can appreciate the great opportunity that is presented. If you don't like the family business and don't want to work hard you will not view this as a great opportunity and might even view it as an attempt by them to control you beyond the grave.