What you *will* find are instances with no apparent violations. Just like setting all the nuclear weapons to have the exact same easily remembered activation code didn't actually lead to a nuclear exchange.

This isn't a great example. Not even a backdoor. That's an example of weak security, at the final stage behind multiple layers of extremely strong security. If an adversary had got to the point where they were at an ICBM bunker console, and the only thing stopping them was a 4 digit code, it was already basically game over.

The backdoors our corporate oligarchs want have zero safeguards, and once discovered grant any attacker the keys to the entire kingdom, remotely. It's more like the only security being the 4 digit code. It fundamentally weakens the security of everyone, and every system we rely on, to the extent any attempt to do it should be considered a direct act of war against us — as treasonous sabotage, that only our worst enemies would attempt.