Well, avoiding the deeper philosophical waters, I would say whatever responsibility is there would depend on how democratic the country is. Russia is very far from being a functioning democracy at the moment. Sure they have elections, but they're likely partially fixed, freedom of the press is a joke, political protest is punished harshly(typically with violence), and opposing political candidates are prosecuted on false charges, jailed, even killed. Given this, I think holding the Russian people as a whole responsible for the war seems unreasonable. Certainly there's some responsibility there in various ways in terms of the personal contributions of individual people. But precisely because Russia is so undemocratic, the distribution of responsibility is heavily distributed onto the oligarchy and military leadership.
But like you say, genocide is never justified, no matter what. And that was mainly what I was reacting to.
