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.
I think if we drill down to the real issue here, it's really this: How much control should an instance have over what it's users see and interact with?
Some folks want to be the ones to decide for themselves what they see and interact with, with minimal to no interference by the admin.
Other folks don't want to see or deal with objectionable material, and want the admin to ensure they don't have to.
I think the answer is somewhere between, myself. As others have pointed out, botnet instances and instances with illegal material should be defederated without mercy. Instances with little to no moderation and users that are causing problems on other instances should be considered for defederation too.
Whether to consider other cases of defederation is where it gets greyer to me. An instance that has communities that post questionable stuff, but doesn't break that instances rules, is one such grey area. And to be clear, I'm making the case that those communities and questionable stuff live on that instance.
To other folks, that wouldn't be grey, and I guess that's what we're really discussing.
Is it possible to ban an instance from my user level? That is, can I prevent myself from seeing their posts and comments on this and other instances? If so, then Blocklists might be the way to go. Sign up for a "no Nazis" list or whatever.
Why are you trying to view everything and ban things you don't like instead of viewing your subscriptions and only joining communities you do like?
I want to see what communities are out there and active. I'd rather not be stuck in a walled garden of my own making. My default sort is currently Local/Active, but I'm still playing with it.
I also want to see communities out there, but instances defederating makes it a whole hell of a lot harder because it kills visibility of those instances. I don't want to have to swap between a handful of accounts to just have basic functionality all because moralizing assholes want this to be like reddit