I don't have any direct knowledge regarding Indian culture, but I will say that every culture around the world is in constant change whether for the better or not. Your culture isn't the same as your parents' culture or their parents' culture.

Just to use US culture as an example, depending on the point in time you refer to then modern Americans could have still been a) owning slaves, b) denying women the right to vote, c) sending children into hard labor, or d) yelling "23 skidoo...." Luckily we do any of those things anymore. But to the people who lived in those days they'd see nothing wrong with those behaviors and may actually take offense that modern Americans look down their noses at all those things.

I think they prefer to be called native americans.

I remember reading an article, and I wish I could remember exactly where I read it so I could post it, but it was about an old Indian American woman who was the last member of her tribe that spoke the ancient language. To me, it was such a sad article. She was 80'ish years old and other people were racing to get as much of her knowledge down; from the language to the old stories, in a desperate attempt to save it.

We've lost so much of the culture of the indigenous peoples in this country.