20Death Star Destroyer
Yeah, it was for the greater good, but at what cost?
The Empire is full of bad people with ill intentions for the rest of the galaxy. After all, their pet project during the original Star Wars was to use a moon-sized gun to blow up a planet and destroy millions of lives in an instant. But isn't that basically what Luke did?
Skywalker saved countless lives by destroying the first Death Star, but he also took at least a million lives in the process.
Look at Finn — he's a stormtrooper, sure, but he's also just a janitor trying to do his job. Not every Imperial is a mustache-twisting villain who deserves to be blown to smithereens. Some of them just work there. Luke might be the galaxy's savior, but fans tend to forget that he's kind of cold-blooded.