It comes down to jealousy. Coach K runs a clean program and he wins with clean-cut, model citizen players. So because fans have nothing of substance to criticize them on, they have to grasp at straws and come up with stuff like, "ugh, the refs just want them to win" or "Coach K is a jerk who swears too much when the camera is off him."
Also, the jealousy definitely has an underlying racial element to it. College basketball is a sport that is followed in large part by middle class white people. Duke wins national titles with many middle class white kids. So when John Q. Fan sees that a Duke player is athletically and academically their superior in life, it annoys them to death.
Not many people hated Jay Williams, Shane Battier, Elton Brand, Trajan Langdon, Shelden Williams, Nolan Smith, etc.. but people just DESPISE Christian Laettner, Wojo, J.J. Redick, Greg Paulus, Jon Scheyer, Kyle Singler, the Plumlees, etc. For example, I went to a Duke @ Maryland game in 2009. The stuff I heard coming out of people's mouths about Scheyer and Singler was beyond inappropriate, but I never heard a single negative word about Nolan Smith, an All-American.
In conclusion, I hate Duke and I love the fact they lost tonight.