Also did you look at the instances in question yourself?

No. I’m operating under the principle that anything that I have to experience by going elsewhere practically proves that it isn’t causing a problem here.

You are aware that defederating from an instance won’t stop individual users from that instance joining yours?

If defederation causes objectionable people that would otherwise leave the remaining network alone to – because they were defederated – to come here and everywhere and not leave other instances alone, then the best move from the network’s perspective is to remain federated. Right?