Thank goodness. The military exists to be ready for combat, period. We have made enough compromises in the service of political correctness.
There is no right to serve in the military.
An individual transitioning genders simply cannot be considered militarily ready. A biological female who assumes a male gender will, on average, be less capable than a biological male, and require significant constant hormone therapy to maintain even a facade of being male.
A biological male who assumes a female gender will, once they start hormone therapy, be less capable than a biological male. They may on average be more capable than a biological female.
Both male to female and female to male sex reassignment surgery is actually multiple surgeries each requiring a long recovery time. Female to male sex reassignment surgery is significant and invasive: mastectomy, hysterectomy, multiple cosmetic surgeries. Depending on the cosmetic surgeries it can require months of recovery time and cause permanent damage to tissue donor areas.
The idea someone going through this does not impact military readiness is in denial.
I almost forgot. First, sex reassignment surgery is very expensive.
Also, I failed to discuss the impact of transgendered individuals who do not go through with sex reassignment surgery.
In this case you have a female gendered individual with male genitalia. If treated as a legal female, this means during an observed urinalyses drug test (military standard for random drug tests), the biological male/female gendered individual must be observed by a female. Likewise, a biological female/male gendered individual must be observed by a male.
While the military has moved aggressively away from shared barracks and “gang latrines” with communal showers, they still exist on ships and in forward deployed areas. In these cases, the biological male/female gendered individual must be use female facilities, and the biological female/male gendered individual must use male facilities.
This is not a case of disappearing into a shower stall at a university or a gym. Expect no privacy at forward operating locations.
We have entered an era where most of the people who have voice their opinion have never dealt with this. They had their own room growing up. Even if they lived in a dorm in college, they did not have communal showers. They probably never even shared an apartment with a roommate as a 20-something. They never lived in austere environments. And they want to make policy based on their life experiences.