Not everyone likes to show off. Besides, I'm more into functionality than aesthetically.
Not that I don't care about personal housing. When I do have the chance, I would love to enjoy the perks of it.
But gardening is a whole different thing. You like majority locked out of having the chance earning their own gardening if they're unable to have personal house or need to be in FC which even need to queue in line just to have their chance of gardening (and who knows what happen if FC senior decide to makes things more difficult)?
And for last, look here:
http://wiki.ffxiclopedia.org/wiki/Mog_Garden