Yes yes yes - you're completely missing the point. The point is that it's easy to come up with some sort of contained scenario in which you can devise a perfect

Yes yes yes - you're completely missing the point. The point is that it's easy to come up with some sort of contained scenario in which you can devise a perfect technical solution for a well-defined problem. But it's hard to get groups of hundreds of people to always behave perfectly according to protocol, every time, everywhere, with not a single slip-up over several years.