A competency model defines what each person in their role needs to be able to do, specifically, in order to perform their part of corporate strategy.
But it also defines what it looks like to be great in that role. If you look at the research, for example, Dan Pink’s research in DRIVE, it is a human characteristic to be motivated to mastery. It’s why we work on our golf game or learn musical instruments for fun. It’s why open source software and Wikipedia exist.
How you use competency models to motivate employees that may not be motivated by the organization’s mission is that you make the competency model accessible, and assessable. Once someone sees what they “should” be able to do (in the competency model), and they assess themselves against it and become aware of any gaps, they want to fix it. It is a totally different dynamic when you want to fix something, versus when someone else wants you to do it. Intrinsic motivation is the most effective and creates the best environment for learning transfer to occur.
If you motivate someone to be great in their job, and the competency model defines what they need to be able to do in order to perform their part of corporate strategy, then by default, using competency models will drive the organization’s mission, even if they are not motivated by the mission itself.