Drowning all life on Earth would seem to fall into that category. It's hard to picture a smiling, jolly old God doing it. That said, it doesn't actually say that, so perhaps it was more sad resignation than anger and vengeance. Nonetheless, chansen's point is that many, perhaps most, lifeforms on this planet that would shrug off a global flood (basically anything that lives it's entire life in the sea/water, though ducks are not the best example). Only life on land would actually be affected. If destroying all life on Earth ("destroying the Earth" as the NIV translates it) was the goal, a flood was actually a poor choice of tactic. It does make sense, though, if you look at it in terms of the people writing it. "The Earth" to many ancient cultures meant "The Land" and, indeed, a massive flood would affect all life on the land. So perhaps taken from that standpoint, the problem goes away.
