P.s. A person will delete their account for any number of reasons: to get off a bazillion neverending threads they once participated in; to force themselves into a break (can also use ColdTurkey for that); because they don’t want to be involved anymore.
Tip: If any of these are true, and you don’t want your *posts* showing your old name for all eternity, change your username to something random before deleting your account and becoming Guest. (I *think* this changes our posts’ author names, yes?)