I am certain the lots are kept simple so that people may alter and change them around themselves. The furniture seems to be nothing more than a guideline, a starting point. I have seen this complaint with StrangerVille a lot and it confuses me. Do people actually care about the houses in the game? Most people simply demolish them, others build around them, and some just replace them without even looking at them.
I have never looked at a house and been like, “Wow, I wish this house had _____”. I can just add it myself if I desire or do what I want. They have said multiple times that they do not want to dictate how people play.
Also, the lots have to be somewhat simple for those with low-budget computers. Each item increases demand that is needed by the game and if you open a lot with hundreds of items, it can really strain some computers.
In the end, does it really matter? I just watched lilsimsie whine – yes, whine – about this issue for twenty minutes. I just cannot fathom how a house being copy-pasted or lacklustre in furniture is worthy enough to bother you when you can spend five minutes and fix it up.
As for the bathrooms, a lot of mansions, manors, and estates often have more bathrooms than bedrooms. A friend of mine had six bathrooms in a three bedroom house.