According to some interview presented on this forum on video, it was amazing how much fear Mayweather showed towards a fight against Margarito. At one occasion he almost cried because of people demanding this fight. He did all he could to avoid this fight. I have never seen a boxer acting like that. I am not sure that PBF could handle Margarito`s pressure for 12 consecutive rounds without being punished. Another reson is that Margarito does very well against smaller fighter such as Mayweather.