If they were brought to onto US soil, they would be treated to the full rights granted by the US Constitution. Also there would be a million watchdog groups on their doorstep watching every move that was made, not what the military wanted. If the camp was in some other western nation, it would be pretty much the same thing. By putting them at GITMO (in Cuba) they are isolated making it very difficult for outsiders to watch what is going on and Castro can't really complain, he has too many other problems one being the very existance of GITMO.
And I don't think keeping people in cages, exposed to the elements thousands of miles from home is mollycoddling them.