The extension point does not require that all subsystems must be mapped to a server that is of the IControllableServerBehavior heirarchy. It's possible to register a service for a tomcat server if you want, even though we don't control their heirarchy.   

This might not make sense for the primary systems (launch, shutdown, publish, etc) but if a new system type were created, it could still be used.  So moving this method up does not make sense in this case.