We have a trait for sims that love water. Why not a trait for a sim that really does not like water, then letting them live on the little island in Sulani o:)
There so much more we could do! When sims are only characterized by what they love they end up feeling one-dimensional. Also your sims end up overly happy. Indeed modding away the happy moodlets from decorations on lots was one of the two things that got me into modding. I just didn’t get to see my sims being bored, or angry or sad. It was just inspired or energized or happy happy happy. That got old fast.
Having fear being one of the driving-forces could balance this a bit but I don’t know if they dare to mess with the system and add that. Perhaps just adverse traits could be done.