This was stated as how it would work during the q&a. If you use less than a full star cap ship on defence or don't fill the reinforcements you give away points.
Old gac it made sense to place your lower star cap on defence as you still got full points for deploying any fleet.
If you use a cap ship on attack that is not full stars you miss out on points too as you can't get the points for not using a reinforcements slot that you don't have or the points for a surviving ship that you can't take.
With this change it is now a disadvantage on both attack and defence, so I think it is more fair. Star it up!