That's actually pretty accurate when it comes to Steve Jobs. First it was him and Gates and then him and Schmidt. In both cases it was a close relationship followed by backstabbing.
Because Cain and Able stories are more fun. They attract more attention. We haven't evolved much since ancient Rome, we still want to see the blood fly. :)
Because "Large advertising firm expands product line; moves into competition with major hardware manufacturer" wouldn't get nearly as many pageviews.