That misses the point. If you designed a bridge, and you died if it failed in one trial, how would this affect your design process?
It is not possible to extract more punishment on an individual than their death, technically, unless you believe in an afterlife.
It is not punitive and meant to 'correct' the builder; it is meant to 'prevent' the builder from cutting corners.
Not true at all. Not that I'd recommend it, but there's torture, and punishing family. They were far less outrageous in Ancient times.