Now, why did they have that attitude? Let me tell you a little story.
One day in the 1870's, about the time the Sioux rose (I couldn't tell you which time), some Indians -- don't know what tribe, which band -- massacred a farm family who'd committed the grievous offense of farming while white, and minding their own business while white. Men all mutilated, women raped and then mutilated, children just mutilated, everybody scalped and dead. My great-grandfather, a young Irish kid who'd come out from Indianapolis where his daddy was a hotelier and his brothers were drunks in Daddy's hotel bar, was a white scout for George Armstrong Custer's Seventh Cavalry -- yes. The Seventh. They mostly shot buffalo, rode with the troops, and tried to stay out of trouble.
They heard about the farmstead massacre, so they rode on out to see about it. A baby boy was unaccounted for (I do seem to recall it was a boy), and it was thought that one of the raiding band had taken it with them.
Riding out following the Indians' trail, they spotted an Indian woman, a young woman not a squaw, sitting by herself under a tree -- nobody else around, all by herself, except that she had a baby with her. A white baby: they'd found the missing baby. They rode up to where the young woman was sitting, dandling the baby, and my great-grandfather looked down at her and she looked up at him. He said afterward he'd never forget the look in her eyes -- cold, black, bottomless wells of enmity and implacability. And without even looking down at the baby, in a twinkling she produced a knife and in one, fast movement, gutted that baby from crotch to neck, just eviscerated him. Great-grandfather said he didn't know how many times he and his companions shot her, but it was a bunch: they shot her to pieces.
That was what it was like to meet an Indian on the High Plains in the 1870's, if you were white. Now take the rest of it, and shove it. Not buying any of the white guilt you're selling.