Simon liked Carmen at first. During the first several episodes, he praised her. When the bad talent was gone, and he realized how bad she really was, he only had one choice but to get rid of her. So he decided not to like her. Believe me, my mother and I sat in amazement as he praised her. I watched and heard with my own eyes and ears.
As far as not believing they fix shows--I think I've seen they don't have to. The public already believes they do, so they don't have the need to. They can get by simply on assumptions.