It's definitely one of the better depictions of early Native Americans on film for sure. I do, however, have problems with the way John Smith is depicted and the "Making of the New World" documentary where they tout how accurate everything is. Smith was in no way a brooding, moody, contemplative figure like Ferrel. He was a straight up alpha prick (and an ugly mofo too) and had major implications on the Powhatan populace (and people further up the coast). Historical accuracy with costumes and settings is one thing, but to diminish the actual conflict to serve the love-triangle story is disappointing. It's a pretty film, but in no way is it culturally enlightening.
It is my favorite film and I believe you are misunderstanding its intentions. Malick is philosophy, philosophy, philosophy. He's not a historian, nor an anthropologist, and he's not trying to offer insight into past culture or a critique of current culture. He is inviting you to take a personal journey inward to ask yourself what the characters ask themselves about throughout.
The New World explores...
-Love
-Commitments
-Communication
-Identity from your past experiences and actions (Smith)
-Identity from your people and foreigners (Pocahontas)
-Identity from what you learn about yourself and life (Pocahontas and Rolfe)
-Structure of society (social roles, rules, religion) vs Nature of humanity (appropriation, curiosity, need)
-Desperation (emotional and physical)
-Jealousy (emotional and physical)
-Conflict (emotional and physical)
-The accidental/automatic nature of both sorrow and strength
-Discovery bringing the death of what was (past of those cultures, Pocahontas' past identity) and birth of something new (Pocahontas' English cultural identity, her son)
-Humanity in general, both cultures and the individuals within them, as a part of nature (the final and universal identity) in the cycle of life.
That's not even everything, it's just an outline of the major components. What this film skimped on because it had a love and identity focus, he explored in depth with the Thin Red Line before and The Tree of Life after, but the three altogether make it very clear what he is after.
The films are not about the plot; they are, ultimately, about you. That is why they are so sensory and fluid in their direction, because the focus is on how you experience them rather than a specific way to experience them that he is trying to force you to use. If you're looking for (or seeing) intentions of his other than to vicariously inspire the feelings and questions of the characters in yourself, you're looking for (or seeing) something that is not there.
Disney's Pocahontas for adults
I thought that was Avatar.