No, I was responding to the "no one in their right mind" bit. It seems to me that when you are in your right mind is precisely the time to build artifacts that could destroy your civilization, and it doesn't seem to me that you could conclude from building such artifacts that you are not in your right mind.

Rather, I think there's other evidence that humanity can't be trusted with e.g. nuclear weaponry, and this suggests that we should not build it. lukeprog's quote seems to me to be of the form "Humanity can't be trusted with nuclear weapons, yet builds them anyway, so it must be crazy, so it can't be trusted with nuclear weapons."