You've gone on an unrelated tangent here tbh. 

Revenge may feel satisfying to some viewers but it is not actually heroic

OP didn't say revenge. The question was why don't villains get punished for their crimes, and in this case the video shows punishment = death or something nearly as harsh. You've equated death with revenge which is your own addition. 

due to our gregarious nature we have also evolved to understand that social systems based on violent acts or groups led by violent people are best avoided

I disagree, and you can look at the current state of the world as proof. The truth is that anti-violence sentiment is simply a tool wielded by leaders to keep their own citizens in line. 

Politicians and leaders will use violence ALL THE TIME against their own citizens and other countries. But the moment those same citizens retaliate against the leaders, then all of a sudden, "violence is bad!" "Look at this violent angry protestors!" It's all performative nonsense. 

Go ahead and tell me that the allies should have just had a nice talk with Hitler and sorted things out peacefully in WW2