Lets be honest, if you visit the FC wards theres a remarkable number of undecorated small/medium houses owned by FC's with maybe 2 people in them at most. It's obvious what they're using them for, and its not for the enjoyment of owning a house. They're either passively farming gil on their 8x FC houses per world, or holding onto them for resale.

The question is, why isn't it harder for an FC to get a house? Under the current system its harder to farm the gil, rather than unlock the privelege of buying housing on behalf of the FC. At least with personal houses its locked to one per DC, per account.