You're making things up. Gitmo was specifically designed to operate outside the US justice system.
After all this, you're still not getting it, are you?
There is no justice system
in the world that is equipped to handle this new kind of warfare. When the standard criminal justice systems have attempted to deal with it, at best, the result has been trials that lasted for years and cost untold millions of dollars, and that's for Zacaraias Moussauoui,
who pleaded guilty. At worst, it results in terrorists walking free, as in Indonesia and Germany.
The big problem in dealing with them through the military justice system is that these people don't follow the commonly-accepted rules of warfare, and our laws and treaties aren't (yet) designed to deal with that. There aren't (AFAIK) any specific rules, either in the U.S. laws, or in international treaty obligations, that set out exactly what you do with someone captured on a battlefield who isn't a member of a GC signatory. The GC's provide for what to do with POWs and how to treat them, but they say nothing about how to treat combatants not covered by the GC.
So you end up running into issues of consistency whether you treat them as civil criminals or military POWs. If you examine a platypus and base your examinations on your assumption that it is some kind of duck, you run into problems. And if you base your examinations on the assumption that it is some kind of beaver, you run into different problems. And if you base your examinations on the assumption that it is some kind of hoax, you run into entirely different problems. Eventually, you acknowledge that what you are examining is something altogether new, and you need to apply new rules.
That's what you have here - a new kind of beast for which the old rules of engagement are inadequate. Eventually, we'll figure out a way of dealing with them that balances fairly the requirements of justice for them and the requirements of security for the rest of us. But until then, the requirements of security will have to trump the requirements of justice - because you can't even begin to have justice if you can't protect the justice system from physical destruction.
Meanwhile, so-called friends will compare Guantanamo to the gulags, Bush to bin Laden, and the U.S. justice system to Stalin's and Idi Amin's. If you want to really be our friends, why don't you tell us a way to deal with the guys in Guatanamo that frees the innocents and only the innocents, locks up the guilty and only the guilty, and does all of the above expeditiously and without bankrupting the treasury?
I'm all ears.