Interesting stuff, and I would agree that just about everything you mentioned was ignorant in some way, though I'd consider a Cinco de Mayo beerfest pretty harmless (don't know what a Japanese space wedding is or could possibly be). But, no, vaguely dismissing the entire free love/hippie/'60s movement as willful oppression of Native Americans indicates to me someone who has so immersed themselves in political correctness that they've melted the common sense synapses in their brain. If anything, the hippies were an homage to what they considered a better lifestyle. In some places I'm sure the movement occasionally crossed the line, whatever that line is, but not to the level of, say, the name "Redskins" -- at least not that I've read about. Honestly this is the first time I've ever seen anyone assert that '60s culture was a racist attempt to belittle Native Americans. Is that a common belief?
Yeah, I'd say your friend has the wrong target there. My experience has been not seeing much mention of Native Americans at all among that culture. Most people seemed to consider a somewhat sad and hopeless topic. But the "other" Indians do get a lot of disrespect from hippies today. Maybe more-so nowadays than in the '60s, but wasn't more than a twinkle in my father's eyes back then, so I can't really comment on that.
Ironically, a lot of leading Buddhist scholars got quite angry with Kerouac and the beats who he introduced to eastern philosophies -- said his interpretation was insincere or insulting (for instance, he was an alcoholic the whole time, which they viewed as hypocrisy). From reading his books, I never got a vibe of disrespect at all, nor exactly one of ignorance... he certainly wasn't malicious or unintelligent. But nonetheless I understand why the scholars were angry. As for hippies today, I have no idea. Hippies today are a pretty sad bunch it seems like.
I can't speak for hippies today, but I certainly was well acquainted with them in the 1990s. I was deep in the midst of hippie culture in Missoula Montana. It was quite possibly one of the leading hippie areas of the US at the time, which was cause for many a cultural collision as most of the state is populated by either Cowboys or Native Americans. The hippies of Missoula in the 1990's were dicks. Uncultured, uninteresting, one-dimensional dicks.