It seems weird to me that you're on the meta for another instance complaining about a decision that doesn't affect you.
There's plenty of other comments here about other awful shit going on at lemmynsfw and I don't feel like recapping that. From what I can see concerning the actual defederation, it is at worst the right choice for the wrong reasons.
The rest of the argument seems to be about the community's intent. Including "child-like" in the sidebar of a porn community because it was copy/pasted from a dictionary definition may have been a 'stumble' but it was still negligent.
Wow that looks amazing!