Violence is a form of escalation. One should never cause a conflict to come to a new height and should only resort to something if in response to anything of that same height.
Also, if a ruler of a nation resorts to that, it shows they’re not a great/effective ruler. Fluency in how to rule is determined by how much peace you can accomplish with as little change as possible. Less is more, as they say. If you have to punish people too often like some are doing, you’re violating that “less is more” rule.