Agree, it's a crisis that has been building for a long time. I was surprised to see a japanese player playing 10 for Canterbury the other day. If Canterbury don't have someone coming through the Crusader academy, it's a bit concerning.
I think a major issue in NZ rugby is treating almost every 10 in the country as a 10/15 hybrid and thinking that game time at 15 will prepare them for games at 10.
Then when young players get the opportunity at 10, they are unprepared for the lack of time and space.
I think young players need to be given time to settle into becoming good 10s. Watching Plummer this season was a great example of that, even though he has been moved around more than most, with some consistent time there he was able to shine.