Oh, I know that it's historically common occurrence, I just mean it's a really strange thing to be advocating for in conversation these days (at least among reasonable people).
It's not that rare an attitude, at least in the less-lethal form of thinking everyone should separate and that the 'other' should be driven out of your lands (and go and make their own country someplace else). Wanting to
kill all of them as our overexcitable poster claims to want is pretty extreme, granted, that puts you up there with the Nazis (certainly if you ever actually tried to put it into practice, rather than just raving about it).
But the slightly-less-murderous version is not uncommon on both sides in Israel/Palestine, for example. Nor was it in the former Yugoslavia, and it's what a lot of both the white right and the more militant - and maybe more pessimistic - political groups representing ethnic minorities in the West claim to want.
(It's how partition came about in India in the first place, and it seems as if the impulse is still there in that country also).
Probably the "get out" mentality shades into the "kill them all" one. The threat of killing is one way to get people to go someplace else.