Due to the fact that the cross drilled holes are perpindicular to the motion of the braking surface, there is negligible air flow through these holes. The fins on the other hand supply SIGNIFICANT air flow.
Yes it is true that the area is a key factor in an ideal situation, but since there is no air flow past the area in the inside surface of these holes, the effect is negligible.
Again I will say if you want to justify using these rotors because they look cool, then be honest with yourself and admit that you are buying them for their cosmetic effect. If you think you are functionally improving your brakes, again be honest with yourself and save your money.
Have a great day,