"It" is major media hype, when major columnist proclaim you have it. I don't know if you watched the Nuggets and Thunder series, but Kobe didn't have "it." He was awful in the clutch, but because he made a big shot here and there in the past, and has rings, it was enough for the talking heads to proclaim he had "it."
I'm sorry, but I really think people are swayed by the major hype they are given. Looking at the numbers, none of those guys really have "it." Except LeBron, who has been the more efficient player in clutch situations than either Kobe or Wade. Looks like statistics bust the preconceived notions....