Because the larger an organization grows, the fewer and fewer shared values employees in a company have. A small organization can be very value-driven: ideology is easily aligned between 10 people that have selected one another directly.

At a certain scale for a corporation, the only value that people inside a company share is the desire to make money. Literally the only value. Nothing else matters to everyone. Of course, every individual or small group will have their own unique set of values, but the only value and incentive that is aligned across everyone in the company is the pursuit of money. And so businesses, without fail, converge on this singular focus, no matter what the company convinces its employees or consumers it values.