Caliban is the true savage because he lives outside of society and he tried to rape Miranda. That crime makes him a reprobate. Although the other characters are hardly beyond reproach, they are not as bad as Caliban. A lot of them are criminals, but they are not truly savages.
The fact that the courtiers believe themselves superior to the indigenous islanders provokes an assumption of ignorance on their part, but we can't disregard the fact that such such thinking is congruent with the (at the time contemporary) "Chain of being" view which affirms, for the most part, their divine dominance. On the other hand the fact that Antonio's acquired his kingship through treachery and usurpation leads me to believe that perhaps human nature, according to the corruption of the western colonialists societies, is prone to such ill-mannered thinking which may lead to dystopian endpoint in which power & ruler-ship become seemingly unstable.
Just one man's opinion though, apologies if I went off topic.