Try being a little more intellectually honest about the situation. No one was "simply pulled off the streets of Bagdad". There are basically two types of detainees. The first were captured while actively engaging our troops or Iraqi police. They are by far the larger group.
The second were men captured in raids against places suspected of being terrorist/insurrection strongholds or safe houses. These men should have been held separately, investigated by military tribunal, and either released, handed over to Iraqi authority, or kept as enemy combatants as determined by evidence. We neglected that process. Then when they were transferred to Guantanamo they were handed over to the CIA - a non-military agency - for interrogation, thus essentially releasing them from military authority. Because they screwed that up, it becomes a civilian matter, with all the associated political controversy. Had the military higher ups done their job, those who were transferred to to Guantanamo would have been already classified according to evidence as enemy combatants, in which case the only issue would be using torture as a means to gaining intel. The question of holding people without trial would be moot because their status would already have been determined through military rules of evidence.
As for "simply defending their homes" - that is a feel-good boogie. If they were engaged in activity to harm our troops, they are enemy combatants by definition. I no more agree with the invasion and occupation of Iraq than anyone. But the fact is we are there, and there are people trying to kill our people. Whether our purpose for invading and occupying another country is justifiable or not, there will be people who will try to defend their homes. People intending our troops harm cannot reasonably be ignored or released because we "agree" with the principle of their motivation.