I'd say its because every country only has a very limited supply of top level sports people - and all of ours play other sports. People with the natural ability, reflexes, vision and freakish athleticism of say Carter, the Smiths, McCullum or Shaun Johnson could have been our international football stars. Instead they (and most other high-level NZ sports people) chose other sports. Mainly because all their top level sporting friends did the same, but it is also that they are better pathways to professionalism.
You can coach the shark out of the next tier of sports people all you like, but they aren't ever going to be as good as the best of the best.
How do you change that?
Maybe the backs, but our attackers (excluding Wood) are too small to play rugby.
Yeah heaps of kids grow up playing football and amount to nothing. Heaps of kids also grow up playing rugby and amount to nothing. That's irrelevant. The point is that in countries where football is the dominant sport most of the kids who are naturally freakishly athletic with great balance, hand-eye coordination, reflexes etc are going to play football. Here most of those kids aren't playing football because football isn't the dominant sport. For instance, at my school there was a guy who was a national sprint champ, and he played on the wing in a rugby team, not on the wing in a football team. His equivalent in say, Iceland, would be on a football team. Flat out sprint speed can't really be coached in the same way technical ball skills can be,