I honestly think most of our youth products are just shit to be honest, just like Shane, who even couldn't start of Birmingham. You can see the youth products from Man Utd or Liverpool etc getting games regularly for championship teams or even EPL relegation contenders, whilst ours can just attract League One at best and sitting on the bench for them. Dummett, whilst labelled as Dumbshit here, probably enjoyed the best loan among our youth products, getting lots of games in SPL, and is probably the best product in his batch --- and yet he is shit.
We did ruin some players who has had massive potential, like Vukcic and Bigi, by not developing them properly. But other than these two, I don't think we really "ruin" much. They are just purely shit. Jury still out for Sammy though.