In the spirit of being encouraged to speak my mind here's a slight effort post:
Defederation does not do what you think it does.
The instance creator and admins are those with the ultimate power within their instance. The active users delegate them that power by interacting with their instance.
Defining "defederation" within the context of Lemmy as I understand it:
"the act of denying the ability for accounts within specific instances to interact with each other"
Anyone at this current time can create an account on most instances. One site on sh.itjust.works is defederated right now, but anyone here may also have an account there, who knows? The value comes from our activity and interaction within each instance.
Defederation is a narrow and a slippery slope because it doesn't actually solve any problems. There are many instances which are doing things I think should be banned. I don't interact with them. I don't provide them with any value.
We uphold an inclusive enjoyable community here by being active. Individuals with malicious intent are ostracized naturally by an active community. Defederating entire instances does not stop bad actors, but an active strongwilled community does.
It's not our responsibility to moderate other instances.
So what you're suggesting works in theory, but not in practice. There are times when simply ignoring bad actors or voting them down within a community is not enough to stop them from misbehaving. Try ostracizing a botnet. Or nicely asking trolls to stop posting racist memes. It won't work.
Oh no, what I'm suggesting is that we can't stop them from here. On sh.itjust.works the best we can do is self-moderate. It's not our responsibility to moderate other instances, and defederating is a bad attempt to do so. Defederating from any instance that has a racist meme is not a good way to deal with that, simply self-moderating well on sh.itjust.works is the best way.
As for botnets that's another story, spam should be against the rules regardless.
Communities within sh.itjust.works seem to be well moderated thus far, and that's great to see.
That's kind of the crux of the issue though, you keep saying "instances should self-moderate" but then you say "defederating an instance that is not properly self moderating is not a good way to deal with that". What exactly do you propose to do then if an instance is not self moderating enough?
Exactly. When TendieMaster69 says "self-moderate" I think defedding should 100% be a part of that self-moderation toolkit. That's all defedding is - an instance saying "nope, we're done with your b.s." I don't see why that should be off the table.