This type of view pretends to be smart, but only until you personally get robbed or mistreated. Then such people quickly learn that sometimes there's black and white. Seen many times.
You only can afford to not think in black and white until you're confronted with, as you write, evil and good, yourself.
As per one of Ekaterina Schulmann's recent talks (I think the one at Science Po) "Q: Do you know which concentration camp they are bringing us to? A: I don't know, I don't bother about politics!"
Vladimir Vladimirovich is going to be remembered as the next Adolf Stalin and for a good reason. Post-1945 world is not magically immune to the emergence of such people in power. Grey morality, especially with regards to genocidal dictators, is a myth that the West fell into because Germany had to be quickly whitewashed into being a NATO ally. Hence the "clean Wehrmacht" myth, the Rommel myth, and more. Now this cognitive distortion plays out with regards to Russia and their crimes, "oh they can't be completely evil, nobody can be completely evil anymore", when that is just a myth. Sometimes we can see the same distortion with regards to China, too.