What got Imus fired

Radio shock jock Imus was fired for the remarks he made about the Rutgers Women Basketball Team. Even though he manged to kill two birds with one stone since his remarks were both racist and sexist, he had said things that were a lot worse before. So I wonder why this time is any different than before. Different enough to get him fired. I wonder what actually got him fired, the racist and sexist remarks, or what he said in one of his many apologies, that he will change. People listen to him because of the shocking things that he says. Afterall, he is known as a shock jock. Would anyone listen to a shock jock that's not shocking? Would anyone hire him as a non-shock jock? Apparently not, not CBS Radio at least.