Weight drained? His last fight was at 150 and he made it with no sweat. If anything, it's going to make him that much better.
150 is not his ideal fighting weight for his age. The fact that he has to starve himself to go down at 147 will weaken him. This will affect very much his reflexes and his strength. He'll be slow and his stamina will be affected. Compare that to Pacquiao who needs not starve himself. The agreed fight weight is a great leveller for the two fighters.
Pacquiao has definitely proved people wrong, but some people thought Clottey and Mosley would beat Pacquiao as well; it's easy to find threads for any fighter that go against the norm, and then point out that these outliers were right. All credit to Pacquiao for achieving all that he has, but I could probably do the same thing for Malignaggi, if you get my meaning, and he's not moving up anywhere any list I'd put him on.
I think if you're really trying to hard to discredit pac then you could make yourself believe what you said above is true. It wasnt just this thread, it was several and DLH was a heavy betting favorite as well. And I challenge you to find a 6-page thread in which people were picking against Paulie at about 8 to 1, and he ended up winning. You know, if it's so easy to find those threads. These were no outliers. Manny was the clear cut underdog because he was vastly underestimated.