I don't know why they put it at Gitmo - could be many reasons, ranging from public safety to size of base to climate to logistics of food and water and medical aide etc. Gitmo is a very large base, and from memory is well isolated.
However, one good reason - this is not WWII and the Left has learned how to use the media against the US interests. These "soldiers" - many fighting under no flag, in no uniform, hiding among the civilian population, targeting non-combatants, (List good enough - I will not complete their list of violations of rules of war), barely, (and arguably do not) fit under normal conditions for prisoners of war.
The Left will confuse the public - hey - the guy was not in uniform - that makes him a civilian, right? Wrong. That makes him a spy. The left is trying to give these guys benefits of our very liberal criminal justice system - this would never have happened in WWII. Imagine how far they would want to go if we had these guys in Texas.
Do you think we gave German POWs lawyers in WWII, and had rules of evidence? Did we fly American soldiers back from Europe for their trials? That is what the Left wants. We shot German's in these conditions (spies), as they shot Americans (spies). Those were the rules, and accepted behaviour.
Also - if soldiers escaped in WWII - would they have set out to murder women and children? No.
We should have kept them in the desert in the Middle East - less attention.
Maybe our guys felt the stress of being that far away would help them give us info - I don't know - Our guys are smart, and have reasons for doing things. Uusally very good ones.
As far as Patriot Act - I am not an expert. However, my understanding is that we loosen the rules a bit very similarly to how we treat organized crime (like Mafia and drug rings). Probably due to their "team" appraoch to crime. Most of what you read in the media is either outright lies or hypothetical "what ifs" that never happen.
Personally I do not have any problem with this because Americans are civilized people. Even with such scum like in Gitmo. On the other hand this practice is seen very skeptical among such allies like the UK or Poland.