Speaking as someone who has a cottage, I have run into the cap on my lawn, but I'm okay with that. I haven't hit the cap on interior decorations, so I'm fine there, but I do see where mansions might need a larger limit, or if perhaps certain items types don't count as 1 full item, like putting down an ink well for some reason counts the same as putting down a large aquarium.

I will say, however, that my storage room space fills up very quickly, especially as I store seasonal decorations, and that could use an expansion, especially as small houses get less storage space than larger ones. I don't see a reason every housing size can't have the same amount of storage room space.