There are some teams, in certain sports, that just feel that it's their birthright to win certain competitions. They may not even be the best team in that competition that year (although both NZ and the South Africans can claim that plausibly). What I saw in New Zealand is that they seem to feel it's their destiny to win on the biggest stage. So do the boks. Nobody in the northern hemisphere has that conviction.
It's sort of what I feel about playing Real Madrid. Often, they're not the best team. But they've just got this arrogance about winning that competition.