No DBA program can claim to train anyone for a job. There simply isn't enough time to learn all the different fields and knowledge needed to succeed in a few years. The DBA isn't designed to pour knowledge but to teach someone how to think. The goal of a DBA program is to improve systems thinking and show them how to use and apply theory so graduates can do this for themselves once they are out in the workplace.
If you are going to be a doctor to the fullest extent you should be one that leads the market through the integration and use of new knowledge and research. That's right...you need to learn how use information and apply it to a business to make money.
The DBA is all about thinking and applying. Graduates should be able to see a system working and all of its components. They would then be able to look at these components and make improvements that impact the entire system.
How one is going to know what to improve is important. There is experience and there is education. It would take 3 Doctorate degrees to know it all! Therefore, you will have to rely on others experience and knowledge.
This means reading research studies, integrating new information and applying it to practical problems within the workplace is important. One will need to be a high consumer of information and use that information to build profits. While not all of the information can be learned the process of thinking about research integration can be completed in a few years.