Because it's a bloody stupid thing to say. BTW, Michael, they're enemy non-combatants and as such are not covered by the Geneva Convention.
I know that they´re not protected by the GC IV. And I would have said that Camp Gitmo is America´s problem. But I understand and share the concerns about this camp. Not all inmates there were captured on the battlefield, and those should be brought to a judge. After all, we shall not give up what makes our societies just and modern.