Realism and the ability to create new situations adapting to the weather is why I want them.
The seasons give a different feel to the game if you ask me.
To explain it with an example: me sitting on the couch in real life, eating cake and drinking coffee with the wood in the fireplace producing those typical crackling sounds on the background feels a lot cozier when it's snowing outside. Seasons in game sort of reproduce that feeling because I can relate to it as I imagine my sims feeling all warm inside when they have the fireplace burning bright as it is freezing outside.
I alter my gameplay a bit when there is weather in game, making the most of each season (having a lot of pool party's in the summer, put some burgers on that grill).
