And having women aboard submarines is a good idea because...???
There is NO good rationale for putting women on submarines and a LOT of good reasons NOT to do that. Just ONE is the effect such an act has on families of the male submariners. Every wife wondering if one of the women aboard will somehow become irresistible to HER husband. That makes for problems at home and increases problems shipboard for the Navy. Mullen is an idiot.
There is no reason to change what works, unless there is confidence that that change produces a mission improvement.