It's pure tribalism at that level, nothing to do with logic or even principles.

In that specific tribe Russia = Good, US = Bad, always and with no case-by-case analysis.

(Mind you, I did once turned a tankie away from that by pointing out that Russia's Invasion of Ukraine was the same kind of thing as the US' second invasion of Iraq so it made sense to judge the invaders in both exactly in the same way. Granted this was back in the early days of the invasion and I reckon that anybody who still remains pro-Russia now is either an authoritarian at hearth or a brainless unprincipled parrot).