Recall questions about the number 600. In Judaism, the number 6 is associated with mankind, which occurred on the sixth day of God's creation...the creation of man. This was/is not a matter of God blinked, and this creation was complete. God was--and still is--shaping his creation to meet its perfection/completeness.
The flood is a setting for the Jewish account of what had been happening in the world, in their society. They weren't living up to expectations, and accepting lower standards of behavior and morals. Look at the story again. What did mankind (or the author of the story) see as their greatest fault? There was one man who was righteous. What was this right way that the rest of society was ignoring. Noah remained quiet. He did not speak. In other words, he was not gossiping with and about his neighbors. He didn't curse. Note Noah's silence throughout the story until...he cursed his grandson, Canaan....
The story of Noah presents two extremes to its listeners. Noah was a man of few words, so few he didn't even bother to warn the people of the disaster that would be coming upon them. Unlike Abraham, he failed to influence the people. And, this righteous man, when pushed beyond his limit (due to his own fault) by his grandson, spoke not words of reconciliation, but a curse, bring about the problem of gossip and cursing that had been their downfall before the flood.
It helps to remember that in Biblical times, people saw words as having actual power, a power that was often being misused. The point of this story is to consider whether your lack of words is the problem...or are the words you do speak the problem. A problem, that in this case continued, causing future battles between Israelites and Canaanites. The theme of this story: Watch your words--the ones you should speak but don't; the ones you do speak, but should not.