Why would you want to have 'development' if you don't get to play against good players?
Because it's not playing against the best players in that age group. You're better off bringing best 18/19/20-olds straight through the senior ranks.
...which is exactly what Edge has done for some years now in a NZ context; and I'm sure Ole would argue that NZ national league is a stepping stone, not a destination; as opposed to NZF's view that it is "where All Whites are made".