"If these "protest" singers had had a scrap of principle they would have just shut the fuck up until the Vietnamese had got the chance to speak in their own voice. And that NEVER happened."

Well, you wouldn't have heard about it if it had.

But I hope that you're excluding Soldier Blue from your criticism. Perhaps you didn't recognise the narrative surrounding the Sand Creek massacre as an allegory for the contemporary Vietnam War. And, of course, Buffy St Marie had a vision informed by her membership of an oppressed minority and by her degree in Eastern philosophy.