They fucking hate Hitler and fascists and dont see todays russia in a good light. I would agree that hexbear is an echochamber about china but the same is true with reddit or other such sites, only in the other direction, where every single action of china gets seen as something they do because they are evil.

And even then hexbear advocates for left unity, which I can understand although I still dont like left wing authoritarians that much more than right wing auths. But that means that there are some "tankies" on it that do have positive views on the UdSSR and the PRC. And would you want to defederate from pro USA instances as well? Because I cant really see many qualitative differences between the atrocities done by the USA and the PRC.