Okay, let's compare it to: Let's not make auto-pilot mandatory in planes, because sometimes a copilot has found that a pilot was drunk when taking off manually.

Even if there was a drunken pilot epidemic that causes 10 plane crashes per year, and autopilot only prevents 1 plane crash per year, it would be ridiculous not to make the autopilot mandatory and rely on its absence to catch some of those drunken pilot crashes.

I don't agree. Why would that be ridiculous?

In the example you give, if the copilot catches the pilot more than 10% of the time, then the swap to mandatory autopilot kills more people than not doing it.

I hardly think it would be ridiculous to want to save more lives.