Romulus and Rathnaar revealed a different side of cause and effect to Kahn as they made him understand why such a heartless decision was taken for the sake of maintaining peace across the empire.
But Kahn wasn't still sold on this. To him, it appeared more like a hypocritical justification to maintain the rule.
It reflected on how to maintain the status quo and authority, the top echelons would even kill every witness and victim to cover up for their failures.
As for the innocent people who died… Their lives were just a commodity.
They were expendable and sacrificed not for the greater good but because the top powerhouses of the empire could afford to.
As Romulus said, they were just a 'number' and their lives didn't mean anything more than that to even the Empress of the Empire.
Why?
The answer was obvious.
Because they were weak.