Expectations.

People don’t expect a country that’s supposed to be a close ally to do actual pure evil.

Russia has always been in a different category. It’s oscillated between being an outright enemy and being a distant, somewhat-ally the West is suspicious of. Either way, Putin was never someone you trust.

When someone betrays your expectations, you have a stronger emotional response.

When you feel like your country is actually helping with evil acts, that’s another layer of emotional response.

But if someone you feel like you can’t do anything about and has always been bad anyway is being evil, again… Well it’s a bit of a “no shit, Sherlock” moment. Doesn’t spark anger in quite the same way.