All I can read in the lyrics is that the land, the trees, and the creed was taken away, which in my opinion is a reasonable complaint, though perhaps fruitless. (Another question is whether the song can claim to speak with the authentic voice of indigenious Brazilians.)

In the video, in contrast, tribal persons of decades ago are being displayed, their nudity symbolizing innocence. This is false romanticism in the bad tradition of Margaret Mead. We would like so much to be a priori peaceful, only corrupted by an evil western culture, thus perhaps reversible. Children and "primitive" peoples are hoped to corroborate those dreams - and rightly refuse to do so.

If 1500-2000 persons can read and write the Kaiwá language, it may not be terminally doomed.