Everyone you listed don't kill people. Very few people consider Batman, Superman, or Spider-Man to be objectively wrong. They consider them to be objectively right, and it's because they're enforcing the law when the police aren't around to do so.

"Law" is just another way of saying, "The bare minimum standard that we as a society will accept."

So when we have a society that sends a drunk driver to prison for 70 years for killing a family of four in a head-on collision, but we don't send people to prison for their lives for gambling with the pensions of teachers, firefighters, etc., for polluting the waterways and the earth itself, of course this is the ultimate, eventual outcome.

The only shocking thing to me about Luigi's case is that it didn't happen sooner.