Why is there a demand for Bunk Beds & spiral staircases

There's not much to spiral staircases in terms of gameplay (though the sliding down the railing is cute), but I like building and at least a dozen times I could have used spiral staircases for what I had in mind. It's what I want the most, but it's probably more for builders? I could do without bunk beds because I don't play kids often, but the truth is I'd welcome any addition lol