The reasoning is there is a provision for the limiting or restricting of liberty in cases of hazard to life, health or safety for things like war, civil unrest, a breakdown of law and order, natural or man-made disaster, unhealthy condition or act of God (not an exact quote). As many national and local authorities around the world, including the United States, declared hazards to life and restrictions of movement it was deemed to qualify for restriction of leave and liberty without compensation.
Yet as USN personnel could come and go between their ships and home, including hybrid crewed ships, it begged the question why, if it was too dangerous for MSC, wasn’t it too dangerous for USN?
I believe the answer from the command was because USN are young and fit while MSC are old and unhealthy. CIVMARs needed extra protections USN did not. Which begged another question. If MSC needed more protection then why does USN come and go and pierce their protective bubble?
It just doesn’t add up. I give the command the benefit of the doubt that they acted in good faith during the initial chaotic and uncertain time. It is better to error on the side of caution. Now that we know more about the disease its long past due to right our course and take the appropriate protective measures.