As the left loves to say, history is written by the victors. "The right side of history" implies that they are willing to commit any atrocity necessary to win. Exterminatus is mild in comparison to the horrors chaos(and progressives) are willing to unleash, and thus wiping out a planet is in fact the Emperor's mercy.
As the left loves to say, history is written by the victors. "The right side of history" implies that they are willing to commit any atrocity necessary to win. Exterminatus is mild in comparison to the horrors chaos(and progressives) are willing to unleash, and thus wiping out a planet is in fact the Emperor's mercy.