To ask, "were the Indians angels or savages?" is about like asking "were the Americans angels or savages?". The question would have to be couched in terms of time, place, and culture. Texas is different than California; the Caddo were different than the Karankawa. To try to generalize any culture as only good or only bad is to oversimplify - and that in itself is wrong.
With statements like this it is no wonder that the young, the impressionable and the ignorant succumb to "white guilt".
The statement may be incomplete but not wrong.
And in this context, it is perfectly reasonable to generalize: the wise noble savage was neither.
Subject to exceptions as in everything else.