Current APIMan UI is a handy aplication. However the potential "customers" might want to provide their own branding / Look&Feel.

Consider this scenario: Company XY has a bunch of APIs for various services. They are using APIMan to provide and control these APIs to public developers.

If we keep only the default L&F (which is OK for internal use) the company will most likely resort to implementing their own UI management with their own branding as they might not want to provide the users of their APIs with generic UI used by all other users of APIMan. Having an easy way to customize the L&F might make the app more atractive (especially for smaller scale use).