Putin is the actual decision maker here, and he obviously has no problem killing thousands of people, including killing and mutilating kids. Maybe the average HN commenter would be more humane.

If Urkaine adopted that position - which they haven't - it's just playing victim. Victims have no responsibility because it's someone else's fault. That is, in fact, irrelevant to responsibility for your actions.

Putin (Russia) is to blame for the war, but that's irrelevant to this issue. Ukraine is still responsible for the consequences of its actions. Putin starting the war makes it legitimate for Ukraine to assassinate Putin, for example; but if killing Putin makes Ukraine less safe or causes other negative outcomes, Ukraine is responsible for choosing the best set of outcomes. Maybe Russia will use tactical nukes - is that what Ukraine wants? They need to assess the risks and make the best choice; blame is irrelevant.