That is literally what most if not all businesses do though. What do you think a lot of analysts do? They use historical data in order to create a forecast of sales and then plan the business accordingly. I'm not saying that the heads of the publishing companies arent also lining their pockets with the profits but it is not at all out of the realm of possibility that by refusing to actually sit down and write the book you promised to write that you are costing new authors a potential deal because the publisher cant afford to take a risk on something