Yes, because there are many ratings (specialties) that require upper body strength. Most women don't have it. It would require many manly dykes to deal with the simple maintenance of a Navy ship, not to mention other areas. Then, there is the problem with menstrual cycles of a woman only ship, not to mention even more pregnancies when in port. There are already too many of them occurring on mixed sex ships. Often times, their male counterparts have to pick up the slack. Think about it.
Additionally, when women live in group settings, their menstrual cycles tend to synchronize. Some vessels would be unapproachable for a week or so (USS PMS).
So in other words, one of the ways to break the fallacy that women and men are equal would be to introduce a few crews with female only complements? Personally, I’d like to see the military revert/improve back to Reagan standards.