How wicked people had become. And His heart was broken. That's the first way that we know God cares. He hurts for us. We don't have anguish in our hearts if we don't care.
Heart pain comes from caring about someone or something.
God cares about us. If God didn't care, I believe that we wouldn't be here. He could have sent the flood and just not told anybody. He could have killed everything and washed his hands of the whole mess. In the late 80's Coca-Cola decided to change their secret recipe.