As I said before, he was a complete bastard. The thing about history is that it divides into two things, people and actions. The actions of Columbus, whatever their motivations and faults, changed the world (for better or worse) but only thanks to a vast logistics system that allowed him to do so. The person of Columbus, however, was nothing really special it was just by blind luck that he managed to be remembered specifically.
Personally, I think the actions of Columbus should be remembered, i.e. the modern establishment of the New World, but as a person he really doesn't have much going for him to celebrate, he was really not that far removed from a lot of other cut-throat 'adventurers' of his time.
As far as the Native Americans are concerned, I don't recall anyone actually saying that anything Columbus did was good for them, in fact, I recall drawing a comparison to the fate of the South American tribes during the age of the Conquistadors.
To be honest, the mistake is putting Columbus forward as some kind of evidence of a 'manifest destiny' for the US, rather than as evidence of how far we have come (and, of course how far still needs to be gone) since those days.
