Why do people use the "damaged goods" excuse with Pac?

Why do people discredit Pac's record? They say Hatton was damaged goods, Cotto was damaged goods, morales was damaged goods. Pacquiao was knocked out twice before he fought any of these guys. So I guess he's damaged goods too. That's probably just another thing that makes Pac great. Even though he gets knocked out he still has the heart go get back up and beat people 2 weight divisions heavier than him.