It's a good idea if they'd occasionally ask you for decorating tips, and then you could decorate the home. I liked how in Wild World they'd ask for a certain theme of furniture and, after you give it to them, they decorate their houses with it.
I think we're past the plain square house designs. I wouldn't mind it if even the default house was a little bigger and had some extra rooms (spaces) you could walk into. Instead of just making bigger squares, the entire surface area, shape, and layout of the home could be customized. This could be big for villagers as well. Everyone could have a bedroom, bathroom, kitchen, living/themed space...
Every breath is another opportunity
to do the right thing.
I know not everyone is the biggest fan of HHA points but I did have a whole house. A nice bedroom, nice kitchen room, nice living room, even a bathroom/laundry room and my HHA score never got very high because I didn't have a bed in every room. Who wants a bed in the bathroom though??