Reason: For someone who's famous, he's not exactly doing a great job being a role model. Regardless whether or not his violent escapades were ages ago, his career should have ended there. With the way things are, if you can mess shit up and make "good" music, people will talk about you = money and fame. And thats just fucked up.
Its pretty much the same as a lot of celebrities involving drugs and violence really. He just appeared on the top of my head at the start because I just plain don't like him.
OR if M. Night Shyamalamadingdong is considered a celebrity, I'd kill his career off too. His work on the Last Airbender was just unforgivable.