There is only one reason to keep prisoners in Guantanamo and that is to avoid having detainees avail themselves of rights guaranteed under the American Constitution. Why should an American administration want this, other than to retain the power to do things with their prisoners, not permitted on American soil, which could include torture.

The current government has argued successfully in US court, that because Guantanamo Bay is on Cuban soil, Fidel Castro is the ultimate arbitrator of what occurs there. Now that's a bizarre concept.

However the government is having a bit of trouble, after seeking this ruling, as it still wants to use the American law when convenient for it's side, in cases where it would like to prosecute.   

The government can't have it both ways

I would prefer treatment in the hands of the Yanks too, I'm not a Muslim, but preferably not at the hands of the military and preferably on American soil, where I could avail myself of a guarantee of rights under US law. The US military has not been entirely exempt from carrying out atrocities in the past and that was in a situation where they were not guaranteed immunity from American scrutiny and law.