It's not a race thing. We've certainly had Polynesians, kiwis, Fijians, etc that have kicked on and been the goods, as we've had Caucasian blokes that haven't been.
There's no denying though that our junior recruitment under Smith's reign revolved around the mentality of signing as many big Polynesian kids as we could to fill the sides regardless of skill level. Sure the Caucasian kids we had in the sides didn't kick on but maybe we'd have more of a chance of some locals kicking on if they weren't kicked out of the sides for bigger and often less skilful imports that also didn't kick on. The more locals we have in our junior sides the more chance we have of finding the talent. Not saying we shouldn't import blokes, but it should be for their skill (I.e. Tapine) and not simply because they're big and Polynesian like we did.
I do think we have an issue producing our own forwards that are capable of making the step up though and it's something we need to look into because it's been a very long and on-going issue.
We were on the right track in the late 90s early 2000s. Produce our own stars but then make a few astute signings (like BK) to fill the gaps we can't ourselves.
I think that's what we should (and seem to be) aiming for in the future. Give ourselves every opportunity to produce our own talent and whatever money we can save by producing blokes that want to stay in Newcastle, salary cap exclusions for juniors/long-term club players etc, we can put towards throwing at signings we need that we'd struggle to get to Newcastle.