An important notion in the Star Wars universe is that, yes, we can all think of situations in which such actions seem to be right.....but they still arent. Especially not in the Star Wars universe, where if you give in to feelings that lead to such terribel consequences....and by coincidence are Force sensitive.....then you start a very ugly chain of events!
O.K., when Adolph Hitler attempted to conquer the world, it inspired fear and anger in the free peoples, mobilizing them to respond with an intent to bring him to justice and/or end his life.
The use of the word "murder" is unfortunate, because in a legal context it has the specific meaning of an unjustified and unexcused homicide; there could never be an unjustifiable and unexcusable homicide that was right, because it is inherently contradictory. However, there are justifiable homicides and excusable homicides, such as self defense, defense of third parties, defense of the realm, and unavoidable accident. There are times in which killing someone is the "right" thing, in the sense that it is the best choice in a field of bad options.
I'm inclined to think that most people attempt to justify more of such feelings than they ought, but not that these feelings are themselves always wrong or useless or counterproductive. It actually might be good to hate what is evil.