Sometimes I honestly think they are focused on making building shells, they don't think about interior practicality. I think this was also a problem with Sims 3 too.
As a builder (mostly Sims 3), making a build practical as well as attractive, to also match a theme was sometimes quite a bit or trial and error. My best builds sometimes were mimicked/inspired by real floorplans. Especially, as a starting point. But it is really hard to mimic real life floor plans within the constraints of building ability.
What drives me nuts is the sever lack of Feng Shui: placing beds, and furniture is strange places since the floor plans of the Sim build was clearly intended for exterior aesthetics first, interior second to not at all considered. I have tried to re-design a few existing builds (trying to keep the exterior intact) and gave up.