Good point. Data is one aspect of making a decision. The other aspect is understanding the industry and environment. Often data scientists give just one variable needed to make a decision. In health care for example you need to factor in a whole host of legislation. You also need to factor aspects of the industry not reflected in the data. As an example doctors not wanting to use iPads is something you can't measure and can't force as company. Even though data analysis might suggest this is the way to go.