The fact is not just to have a visual experience but to have a gameplay experience which follow the day/night cycle.
A divisor of 24 for the cycle time is bad, as it will always be night and day at x time of IRL day.
But cycle will help us to introduce era and daily/nightly quests, nightly mob, closed areas, special vendors, secret areas, etc...
IMO, just for the gameplay side it's a good thing to add.
Weather might be added, we will add clouds on the next release to introduce it, but rain and such will continue. For players like you or for those who may not want to play constantly with weather or with a night layer, it's already possible to hide the graphical effect through a parameter on the client, more explanation will come once we will start to work on it. 

"Time is an illusion. Lunchtime doubly so."
-- Ford Prefect