Your position is relativistic.
One can be a "traitor" against a bad regime, in which case it is not a vice. However, when one is a traitor against the greatest nation on earth, it is definitely a vice.
I find it hard to believe that you have not faulted Hawaiians for joining the Japanese.
Maybe you've just provided a response to your own post. If this was "the greatest nation on earth," then what reason would the South have for leaving it? Maybe they didn't really think it was the greatest nation on earth, after all.
It's important to remember that the aim of the Confederacy wasn't to overthrow the U.S. government. They just wanted to secede and go their own way. Just as the Thirteen Colonies never tried to overthrow the British government -- they just wanted to secede and go their own way.
I find it hard to believe that you have not faulted Hawaiians for joining the Japanese.
How could I fault them? They weren't even Americans at the time, and therefore had no obligations to support the U.S.
IIRC, not one person in the Confederate military leadership or goverment was ever convicted of treason.
I wonder why?