That brings us to another point: We've got people causing wars, commiting genocide, and murdering/maiming innocent men, women, and children with suicide bombs over whose extremely similar religions are best. And we've got brutal hate crimes over people's race, religion, sexual orientation, and a government that deprives certain people of the right to marry "because it's unnatural".
In addition to rape, murder, theft, and all that good stuff.
So riddle me this: If the people before the "flood" were so unredeemably horribly vile that a big, all-powerful guy out in space, who was apparently only worshipped by a small family, saw fit to destroy every single living thing in the whole world except for said family and their pets, then how bad are we gonna have to get for this dude to come and, say, vaporize us all?