PROSPERO The rarer action isIn virtue than in vengeance: they being penitent,The sole drift of my purpose doth extendNot a frown further. (5.1.2)
Prospero is honest here, as he forgives everyone that's wronged him as soon as they're in front of him. It is pretty clear, though, that neither Antonio nor Sebastian is penitent about their awful behavior. Does it make sense that Prospero entirely ignores this?