It's part of modern civilization for the same reason people enjoy it when the bad guy gets punished at the end of a movie. This is the essence of justice, whether you have the stomach to face it or not.
I enjoy watching movies as much as anyone, but that doesn't transfer into enjoying people being hurt/punished in real life. I'm happy to leave my darker impulses behind when exiting the theater.
You can't leave them behind and I'm sure you've wanted someone punished for some misdeeds they've committed. This isn't a bad thing and is an overwhelmingly natural response.