I'll argue that it exists - not everybody who torments a baby has an excuse for it. Of course it is useful to try to figure out what made them do it, there might be a kind of excuse in terms of an explanation of what made them do it (bad childhood whatever). Or why - um, presumably they wanted the land? I think what happened in America is that some people had the better weapons and they wanted the other people's property.
"by playing the blame game"
How is it playing the blame game? A bunch of people killed another bunch of people. There is nothing to play about it. What to do about is another question - I am not even sure what you are worried about. Nobody in this thread has called for any kind of reparations or anything, I think?
Isn't pointing out the history of European settlers exactly what you want: pointing out that Europeans can be bad, too, so we always have to keep asking what makes the "bad" come out? I don't think by forgetting history, we are helping the kind of understanding you seem to seek.
Ultimately, though, I think the bunch with the better weapons will always get and take what they want...