You get nice people and jerks from all schools, but the two most insufferable groups I've dealt with in sports and life are Duke and Georgetown. I don't know if the schools attract jerks or turns good kids into jerks, but it's consistent.
Plenty of other schools turn out grads that over inflate the importance of their alma mater, but they tend to mellow over time. BC and Villanova stand out. But, the Duke and Georgetown alums hold on to their arrogance. I will say, the Duke grads have all impressed me at work whereas I've seen a handful of unimpressive Georgetown grads.
Regarding Upstater's fan ranking of the Big East, it's only Georgetown fans that I think are unlikeable on the whole. I also find most Providence grads to be unlikeable and they have less reason to be arrogant about their school (academically and athletically) than the others mentioned. The others BE schools have a loud minority of jerks, or are a bit rough during games, but are otherwise fine one-on-one. To be clear, that includes are own fans. We have plenty of fans that embarrass us.