they got hit by events OUTSIDE the plans (quick name me all of the quakes in that region 0.5 points below what they got hit with and greater)
Nice fallacy there.
Just because you and I don't know the names, it doesn't mean that the engineers designing the plant didn't have to take other quakes into account.
Typical such a plant would have to have to be designed to withstand an event with a 1 in 1000 years frequency.
Long computations which yield zero are probably all for naught.