Flood: a remedy for corruption?

Another approach to understanding God's motive behind the flood lies in comparison to the surgical operation. If for instance all our body is taken by gangrene and only one cell or piece of tissue is still healthy and it is still possible to rebuild the whole body based on this one piece of biological material(this example corresponds really to a modern-day genetic engineering). Then the professional(God in our example) decide to kill the rotten body in order to recreate it through the one remaining healthy cell. In this case his action is reasonable and even merciful: he loves his creation- he wants to rebuild it!