It would be immensely useful to have a good understanding of the design mechanism. If we knew how the design process worked, we might be able to "design out" disease.
At the moment we are having some difficulty designing out genetic diseases. If our genetic models of disease are all wrong and there is way of designing out failures of biological systems other than very hit-and-miss genetic engineering, then obviously it would be immensely useful.
I suppose you could consider it to be a kind of scientific faith healing. But that is probably blasphemy.
Mick