Automatic deletion is useful and great on main sites, but on child metas it deletes my negatively voted feature-requests. >:(
Can it be turned off for child metas?
There are a seemingly-endless number of bad ideas; we don't really need to archive them.
Of course... If someone writes up a really good explanation for why an idea is bad, that can be worth keeping around.
So if you see a meta question you don't want lost, write a good answer to it.