As human beings, moderators have their own preferences which exist beyond the HN guidelines, and are not meta moderated, except in the aggregate.
When a comment becomes dead, it's because some mods chose to vote it down, and fewer mods choose to revive it. The net effect is an expression of the prevailing culture.
Your question about why this sometimes happens "immediately" is an interesting part of the dynamic.
When a comment becomes dead, it's because some mods chose to vote it down, and fewer mods choose to revive it. The net effect is an expression of the prevailing culture.
Your question about why this sometimes happens "immediately" is an interesting part of the dynamic.