In a private cloud computing environment, it is your private cloud. You create, remove, and configure servers as you wish, on that private cloud, and nobody else is touching it. All the resources can be customized solely for the use of a single particular organization.
Since Private cloud offers a scaleable cloud environment built on infrastructure that is dedicated solely to your organization, it is typically more for customers who require robust database and storage requirements, or have a need for higher security in a more controlled, local environment-perfect for customer's compliant and regulatory needs. Database, Analytics, and high I/O workloads tend to be a better fit for Private.
To summarize, Private Cloud provides the predictability of your budget, customization of your network architecture, and knowing exactly where (down to the server itself) your data resides. Who says having everything all to yourself is a bad thing?