it's easy to say mayweather jr. hasn't fought EVERY top fighters like margarito, vernon forrest, paul williams, etc...but the same can be said about pacquiao's refusal to fight fighters like joan guzman, humberto soto, joel casamayor, juan diaz and so on, when he was at the lighter weights. instead, he fought older, ready to retire fighters like morales and barrera, after they were through with their trilogy. he even picked on the much smaller larios at super featherweight when larios was a lifetime super bantamweight and almost got knocked out!!! like mayweather, he didn't take chances either in risking defeat by fighting other difficult, younger and in their prime fighters.