only an Australian would brutally genocide a bunch of indigenous people

Yes atrocities were committed against Australia's indigenous. You're welcome to talk about that as much as you like. I will however point out that colonists the world over mistreated the indigenous wherever they found them. That doesn't diminish Australia's culpability, but don't throw stones at glass houses or whatever.

at least my direct ancestors aren't convicted rapists

This one is an interesting one. While some of the convicts transported to Australia probably were convicted of rape, it was far less common than things like petty theft, fraud, vagrancy, prostitution, and that type of thing. Violent criminals just didn't make great colonists, and were usually executed.

You'll find that most Australian's wear their connections to this era with some kind of pride. For example the first of my ancestors to arrive here was convicted of man slaughter. He had a drunken brawl in a bar and pushed someone down a flight of stairs, and they died. He was an accomplished clock maker, and worked on the mechanism in the town hall not far from where I live.

He's the only convict in my lineage of which I'm aware, but I admit there may of course be one or more rapists unknown to me, but I suppose I share that in common with most people including your good self.

My comments weren't intended to be a "country pissing contest". I was merely pointing out this particular interaction will be difficult to understand through the lense of American gun culture.