I think the fact we do have a half decent junior set up is the very reason we have all these "young Aussies invading" our speedway teams.
Personally it's not something that bothers me, I subscribe to the fact that if your are good enough you will make it.
As a comparison, every two years the England football team either fails to qualify or fails miserably in a tournament. Who gets the blame? The Premiership and Jonny Foreigner of course. England last won the World cup in 1966, the Prem started in 1992. What happened in the years in between?
My own view is that it comes down to application and dedication.