I think these guys just sucked as a matter of fact. When you are truly a great player, your fate can't be decided by anyone. PJ Tucker was buried on the bench in his rookie season with Toronto so he had to leave for Europe to make a living. But he played so well that he came back a few years later and established himself in the league as one of the best role players around.
I mean guys like Nate Wolters and Eric Griffin left the league years ago, if they are good why haven't they made the come back yet?
In many ways of professional sports, it's either you are the guy or you are not. Can't always put the blame on the development team when the guys they've been working with just aren't good enough players. These guys were late second or undrafted for a reason.
Like I mentioned before, Suns have like 7 or 8 former lottery picks on their roster right now. These guys even in the worst case scenario of their development could give you decent backup minutes, which would've been the best case scenario for guys like Nate Wolters, Eric Griffin, Erick McCree, Naz, Cavanaugh, JWF, Willie Reed and Isiah Cousins, etc.