Interesting to me that the first two stories we have heard on Hugo month are much more focused on relationships than on their fantastic elements. Great speculative fiction is necessarily great fiction. And great fiction tends to be about people and how we interact with each other. The fantastic and speculative elements just help to provide a broader canvas on which to paint those pictures of people.
To me, the water falling was an essential part of this story. The main dramatic tension in the story involved admitting the truth of who you are to yourself and then admitting that truth to others. The fantastic element of the water both provided a story-long metaphor for that tension as well as helped to actually drive the plot by creating a world where truth and lies are made more physically apparent.
The fact that the fantastic element of the water did not dominate the story made it, to me, more realistic. That's how humans are. We adapt to our universe and keep living our lives. Sure, for the first couple of weeks, the world would pretty much stop as people got used to the water that falls on you from nowhere. But then what? We'd have to keep growing food. We'd have to keep fixing our roads. Drilling our oil. Educating our children. Life would go on. Just with the water.
BOSS: "Johnson, I need you to have that presentation for Hardees done by Friday!"
JOHNSON: "But, Boss, water keeps falling on us from nowhere!"
BOSS: "Yeah, I know. Who gives a shit? Keep a towel by your desk. Hardees is our biggest client, our meeting with them is Monday, and we can't afford to lose that account."
If someone from 1930 learned about smartphones and tried to write a SF story set in 2014, he would probably have every other sentence focus on the fact that most of us carry around portable supercomputers that are all networked into a global communications system. To him, that would be fantastic and the only thing any of us could possibly discuss or think about.
To us, it is just part of the universe as we currently understand it. Certainly not more important or deserving of our attention than bringing the person we love home to meet our parents and our mean sister for the first time.