But if you just say "we don't want to be moderators anymore" nothing would change would it? The whole point of the statement is that the mod-team believes something in the organisational structure needs to change.
I would explain what went wrong. It's clear that their organizational suggestions were prompted by a member of the core team doing something they consider terribly wrong - how can it be so bad the Rust community has to know about it yet not bad enough that the community needs to know what it was?
What would you have done in that case?