Obama doesn’t care if the Gitmo detainees return to terrorism. To him, it is a bigger crime to keep these dangerous terrorists safely locked away.
He does care if they return to terrorism. The same way he cares about Iran’s nukes. He cares but not necessarily in the way you would. ISIS needs the expertise he can provide. When the price of oil kicked Iran in the gut, he released all those billions of sequestered dollars to Iran to compensate. He cares.