"You can't take us down! We'll take _ourselves_ down, so there."

If people see the dead reddit dude they just assume it broke and come back later.

If they see a "this sub is private because reddit is dumb and also evil" they may come back later, they may not.

Honestly, looks as reasonable as anything else about this thing.

This is my guess. Looks better on the record, since people are committing only 48 hours anyways (for whatever reason, should be permanent).