"the cost of routinely carrying excess fuel" translated means the additional fuel deemed necessary by the captain to conduct the flight safely and incorporates any additional factors that flight planning have omitted to do, such as busy arrival times at Doha, routinely being held at a lower flight level.... the list is endless.
Just because additional fuel is not utilised does not mean that it is a frivolous waste of company money. For me, it is good economic sense to plan for such events and prevent unnecessary diversions etc.