I wonder did everyone complaining about the size difference say the same things when Oscar kept moving up in weight until he met Hopkins. It is not uncommon in boxing at all for fighters to continue fighting bigger men until they get their asses handed to them. Oscar did start at 130 himself.
Part of the allure of fights such as this is to see if the smaller man can step up and beat someone that it seems impossible to beat. If we never allowed them to test themselves how would we ever see truly heroic efforts? I guess those complaining can't stand open weight MMA tourneys either.
Personally, I would rather see Marquez/Pacman about every six months or so as I love their fights, but I'm not going to begrudge Manny a chance to make a VERY big payday and do the impossible at the same time.
Rather than focusing on the perceived lack of heart of Oscar for taking this fight and not Margarito, why not focus on the gigantic heart of Manny for accepting.