The problem is using the word "steal." It implies illicit, underhanded or even criminal activity. Apple and MS (and Linux) don't steal from each other outright-- they're influenced by and react to each other's innovations. That's just good business, and it goes on everywhere-- for example when Buick first introduced turn signals to cars, don't you think Ford did the same one year later? And can you really call it "stealing" when they did so?