Defamation of the king in Thailand can be something benign like saying you’d prefer to have an elected President.
As for it being a democracy, they have elections, but the military will stop a party from taking power if they don’t agree with them, like what happened last time.
I mean, if you’re going somewhere as a tourist I doubt you’ll get to see inside their prisons and stuff. You’ll only see the stuff that’s super obvious.
If you go to New York it’s not like you’ll get to visit Riker’s.