A server that hands out accounts needs somebody watching the door. When nobody with instance-wide moderation authority has been present for a long time, signups, reports and the moderation queue go unattended, and the server becomes cheap infrastructure for spam and abuse aimed at everyone else.
This FEP is about liveness, not authorization. It does not define moderation policy, does not describe how accounts are suspended, and does not address moderation scoped to a single group or community.