Laurian thats a good point. I would still argue that the principles are valid for enterprise or any type of design.
In the end, simplicity of the product is defined by the end user. If the design process goes from all the complexity and boils down to the needed features in the end than in my book addresses the utility.
For example: Photoshop and Illustrator are good and simple enough tools in my eyes and a spaceship control panel in the eyes of my parents. :)
If you are helping the target audience to finish their task with efficiency then you've taken care of the utility.