But that does fuckall good. Why? Everyone in uniform has relatives who aren't. Whenever one person chooses to publicize their genetic data, they aren't just giving up their own privacy -- they're also inevitably giving up some privacy for everyone else related to them. This is a huge problem.
And if the government is concerned about this issue for its soldiers, that means it's probably a bad idea for other people too, even though the exact risks vary from one subgroup to another.