PS - clue - many of the officers in charge at USNA are parents also.
In addition to the excellent points above, you might consider, the detailers (men and women) will not have it. Ask yourself whether they get graded on their plebes or have a sense of pride in plebe transformation.
Once the detailers find a target that needs some extra attention, training and tender loving care, your friend's summer, plebe year and reputation will all mutate - not for the better. The detailers talk and trade notes (que Col. Jessup "[w]e are going to train the lad.") He does not want extra training or instruction. It will be game on.
Remember, the women at USNA did not get there by being timid. The women are addressed as "ma'am." In closed circles, some may be referred to as A "ma'am" or A "boss" - both terms of respect that come with a healthy sense of fear.
If you really want to help your friend, thank him for being different and choosing the more difficult path. Remind him that the sacrifices he makes now will give him opportunities to do things in the future that most (90%) of the population only dream about. His first year will include instruction (and tutoring) from some of the best minds in the world. If he makes it through plebe year, next summer he will be getting to fly (perhaps in F18 jets) and training on a fast attack sub(s) for a week. All under the supervision of qualified competent officers, many of them women - none if which will put up with that. His college buddies will be struggling to find internships if they do not have to work (or just putting off growing up and partying).
Right now, your friend is growing up fast. Support that. Words of encouragement from his company are things like "embrace the suck." USNA is not college. It is a four-year course in leadership that also provides a degree. But other programs help people to grow up also:.
For you, it may not seem like it, but if you are not making an effort to grow and move forward, you are moving backwards. There is no neutral.