if you look on the dps and the only factor is how punishing the rotation is you may be right that it's fair that DRK does less damage overall.

however, dps is not the only thing a tank has to worry about: dps, mitigation, selfheal, utility. the DRK is behind in everything. if we had better mitigation to make up for the dps loss, fine, i wouldn't say anything. but when WAR gets his aoe shield now he has even better utility than DRK. in the WAR - PLD comparsion the balance gets better, but DRK falls behind now even more.