> This is about human psychology, rather than reliability in the engineering sense. I truly believe it would lead to better safety, but not perfect safety.
The problem is that you have no idea how Process Safety works, or even what it is, judging by your posts. As the parent to this post explained, these major hazard events are probabilistic, not deterministic. That means that they can never be completely eliminated, only guarded against and reduced to the point that the benefit is understood to outweigh the risk. There will always be risk.
You suggest that the engineers responsible for designing the plant should commit suicide if this once in a million year event takes place. What about the businessmen who accepted the risk? Or the government who stipulated what the tolerable risk was? Or the people who moved nearby, aware of the risk? Or the workers on the plant who, knowing what the correct maintenance procedures were to keep the plant safely operational, ignored them because it was 'too hard'? What if the root cause was a vector of risk which was poorly understood by everyone at the time? Or the engineering specification was correct, but the materials vendor skimped on QA? Or were lied to by one of their plants? Or a subcontractor of the plant? Etc etc etc.
What you propose, even as a thought experiment, is futile. Because even if you could reduce the risk to only systematic errors made in engineering design, if there was a perceived need or benefit to design the plant, you could always find a group of engineers desperate enough, naive enough, or vain enough to take on the risk. And therefore society as a whole would not be safer.
As it happens there's a large body of engineering knowledge which goes into making dangerous plants 'safe enough' to outweigh the risks to their workers, owners, and society at large. It's not foolproof, but arguably it does a good job of allowing societies to benefit from the dangerous processes we seem so desperate to use. And don't kid yourself - just because these massive events incur a media feeding frenzy, doesn't mean smaller hazardous occurrences don't affect the lives of thousands of people every year. Should we kill everyone who could in some way be held accountable for another's death or injury?
In short, don't let fear guide you into silly knee-jerk reactions. There are massive problems inherent with dangerous processes, and most of them relate to the very human failures of laziness and greed. We're working to improve the situation constantly, but it's a long road and a constant battle.