There's been a lot of unjustified poor behaviour in history, some relatively recent history.

Jill¹, who I've known since we were both quite young, is barely a generation removed from the Australian frontier wars, massacres for a century+ prior to 1930², something her parents lived through.

¹ https://www.youtube.com/watch?v=_UKu3bCbFck

² https://en.wikipedia.org/wiki/Coniston_massacre

( two geographically seperate references, I know .. it's to carry a point not to join a specific person to a specific event, which could be done )