A lot of people don't want to buy smalls or mediums. My current ward has a lot of empty smalls, and most wards I look into seem to have quite a few even with the occasional medium.

Moving the housing discount on relocating from 20% or whatever it is to 100% would make more people feel comfortable purchasing something while waiting to get their large.

There might be more gil in-game for it because housing is supposed to be some sort of gil sink, but I don't think it would be that big of a deal?