Differences in instance-level topical focus and moderation philosophy, for one. Also physical location and “vibe”.

There are a certain set of bigoted and/or extremist instances that I would judge an instance for not defederating from. There’s a reason I’ve stuck with .world even through some turbulence. Some heinous shit shouldn’t be tolerated by anyone.

As an aside, check out !specialized_instances@kbin.social if you haven’t already.

If someone’s email domain is @ihateminorities.com, I’d say that’s pretty fair grounds for blocking it.

There are some instances that actively promote hateful or extremist content, and exist for the purpose of hosting it. There are others that do not actively support that content but do allow it, anywhere, making blocking one community not enough. Defederation is an important tool and should be used wisely.