I think most people look at the Native American genocide as a tragedy, not "savages who needed destruction". Even my history book thought so.
There have been countless war films and novels and games that have all taken the side of the White colonists and displayed Natives as beastly enemies.
Back when it was happening it was certainly seen that the Native American's were uncivilised savages who simply got in the way. They attacked colonial towns, villages and farms. They would destroy settlements, scalp innocent women and children, disrupt colonial supply lines and more.
It's difficult not to have seen them, back then, as a nuisance and decide to attack them.
It's only now, far in the future, that we can see that it wasn't entirely necesarry (atleast not to the extent it happened), and that we attatch the term "Genocide" to it.
It was Genocide, yes, but back then it wasn't seen as destroying the entire race for the sake of destroying them.
There were acts that the white colonists should not have done. Things they meant to do (such as declaring war and pillaging the Native Americans), and things they didn't mean to do (such as shooting the buffalo for sport, causing it's extinction on American soil, and therefore killing off the absolute primary resource for all Central Plains Native Americans).
They did these things and claimed it was because the Natives were savages.
This is something that was based on fact (Natives had cruelly attacked Colonists, but it's also easy to see why).
The idea of the white settlers being the good, decent people, and the Natives as the savage beasts needing to be stopped became a big part of American culture.
It might not be displayed like that in your un-biased 21
st Century History Books, but everywhere else, it's easily apparent.
How many people have, as a child, played "Cowboys and Indians"? It's quite common that the Cowboy is the good guy, and the Indian isn't.
