Why should Calzaghe be p4p #1?

Everyone was saying before last night that Pacquaio was going to get beat and Calzaghe was going to be #1 p4p, which would have been right if it happened, but it didnt happen and people are still trying to argue that Calzaghe is #1. What actually happened was Pacquiao leathered De La Hoya at welterweight, stepping up 2 weight classes. Fair play to Calzaghe hes never lost but hes stayed at the same weight, and never proved himself in lighter/heavier weight classes, so how can he be p4p #1 when pacquiao has continually moved up in weight and dominated???