No, it’s completely inappropriate for the secretary of the Navy to think he has to go explain his decision to the crew of a ship just for removing a captain. No need for him to go vomit his explanations and reasons all over the crew. And the crew should be expected to follow orders without explanation.
You’ve never been any kind of a leader in a good-sized organization, have you?
Needless to say, I disagree strongly with your assertion. The crew aren’t mindless automatons.