Don't be stupid, this isn't everyday people of Russian origin doing this, it's a crazy quasi-dictator.
If we were to ban people because of what the state that they are subjects of got up to, then we'd have to ban a lot more people than just Russians and Belarussians; there'd be the Americans, because of their repeated drone strikes on innocent civilians in various countries around the world as part of their undeclared ongoing war to assassinate their 'enemies', the British, Australians, Canadians, and Kiwis, for the support their intelligence agencies give America in that ongoing, eternal war on terror that those drone strikes are part of. And the list would go on until the only people we didn't ban were the Bhutanese.
This singling out of individuals because of their nationality (which they can't help) is exactly the kind of tribalism that feeds wars, not stops them.
It's only one step further before we start calling them by loaded de-humanising names like 'gook' because everybody knows that people from that country are all bad, barely human even, and we're doing the world a favour by exterminating them. (The word 'exterminating' was used by TASS in an official press release today to describe what they (Russia) were doing to their 'enemy' in Ukraine.)