the characteristics of these particular people (coaches and players) that he believes are problematic, without trying to ascribe it to race. In fact, I can't for the life of me understand why saying anything about Polynesian culture was relevant.

For example:

"The point is that faithful, humble and a mostly good guy like Reno Mahe, one of Kalani's close friends, is still as prone to making foolish, immature and lazy decisions as he was when he was young. He just doesn't "get it," and probably never will."

Why not just say, "Reno, who is a mostly good dude, makes immature/foolish mistakes, just like he did before he was an adult...?" Instead of implying that "Because Reno, who is a mostly good dude, is Polynesian, he makes immature/foolish mistakes, just like he did before he was an adult..."

Every person is complex and different. Even from within the same ethnic group. Every person becomes an individual from a mix of life influences (family, community, culture, religion, etc.). The characteristics of some of the coaches and players might be as you describe. I don't know. But I can't for the life of me figure out why trying to make it about race is necessary and helpful.

Racist - a belief that race is the primary determinant of human traits and capacities...

This is exactly what the OP does. He chooses to ignore everything else that makes these men who they are, and instead picks the behaviors/tendencies he finds most problematic and suggests that their race is the primary factor.