Cat Stevens is a bad guy. He has done a lot more than just call for the murder of Salman Rushdie.
By the way, Yusuf Islam/Cat Stevens, when asked about his comments on Salman Rushdie recently denied that he ever said such a thing. Too bad for him that we have something called YouTube now. In the dinosaur media days, he could commit taqiyya and get away with it. Now his lies are apparent...to everyone except Stephen Colbert and Jon Stewart...
Most singers from that time were into defining their own morality (another way of saying "If *I* like it it's good, if *I* don't you have to stop"). The totalitarian impulse never dies.