Isn't collective punishment in boot camp primarily used as a tool to increase the group cohesion of the trainees? In that case, it doesn't really fit into the other use cases, and must be argued against individually.

I'm not sure about the actual utility, but in abstract, it fits quite well to my impression of how humans, especially in small, "hunter-gatherer band sized", groups, work. And the military has a special need to create cohesion in its military that goes beyond what would be even vaguely acceptable in any liberal democracy for the general population. Especially in the special case of a criminal: which government would be stupid enough to increase the group cohesion of a dangerous criminal's family (including this criminal)?