The main problem with Gitmo is not that the US went after terrorists.
The problem with Gitmo is that the US simply kidnapped anyone who they 'thought' might be a terrorists, and then held them without legal process and tortured a good number of them, just in case.
Many innocents were captured, and then tortured or sent out for torture.
Due process and laws are supposed to make sure innocents have protection against a government.
Torturing and kidnapping innocents is wrong. Period. No matter who does it.