There are at least two ways in which this is true in today's world.
First, there is the sort of proprietary information that a business wants to keep secret. These are the firm's plans and its procedures. The more its competition knows about these things, the better they can compete with it. This must be kept safe just as military plans and data must be kept safe from enemies in time of war.
Second, today's businesses have a great deal of information about their customers. They have credit card numbers and other such data that are very important. If these data are accessed by outside parties, customers can be hurt. Customers who are harmed will naturally blame the firm that did not protect their information.
In either case, the loss of information will hurt a firm badly. Therefore, a business is not safe unless its information is safe.