I really don´t understand why Square Enix choose this housing system for private houses...even if they would implement a system were abounded houses would get back to the market it would never be enough. And its kinda funny how some people on the forum wants to punish the players instead of putting the blame to the ones that created such a poor system.
A lot of examples for MMOs that have no problems with housing were already posted and its even more sad because one of it even comes from Square Enix...I mean if they really have all those problems with the servers already than I fear what will happen in the future with this game because there will be more an more restrictions. We do already pay a monthly fee and they make money from the cash shop and other merchandise so I really hope that they will put some of it back to get better servers.
Instanced housing for private houses would be the best way to go. If people want neighbors than they can still have them by having a FC house.
Like KamikazeMan said it could be that we start with a small instanced house and could work our way towards a mansion or maybe even something bigger. They even could implement it in the story as a quest from the GC leaders that want to thank us for our help against all those dangers we faced for them. I mean in the end we do so much for them but barely get anything back. So this would be a way to say thank you. With that we may choose a place for our house and it could be independent of your own GC so that people don`t need to change their GC if they want a house in another region.
After that we can make the housing plot bigger and bigger for example by helping a NPC with building up the “neighbor houses” that are only seen (but not really there) next to our houses to make things look livelier. There could have been some kind of natural disaster like a tsunami that hit Limas beach or maybe a dragon attack in Ishgard (if we have private houses there) and we can give them crafted items to help build them back up and in return gain points. And with these points we could buy rare housing items that are restricted to the housing place and buy new license to expand our instanced plots. With this we still have to do some work to upgrade our houses but at least everyone can own a mansion or maybe even an whole island in the end.
I would even say that you may be able to change the place of you housing plot. Like if you were in Limsa before but wants to go to Gridania than you can pay a big sum of Gil and with that your instanced house is changed to look like a house in Gridania.
Another change they need to do there is to increase the maximum of the items we can use in our private house. Because this is still to low. Maybe we could even have the instanced rooms the FC has to gain even more room (this would also cost 300k Gil to get the money out of the system) With that we would at least have rooms with their own amount of place able items. But in the end I would be completely happy if they just gave us our private instanced houses, I would even gave up my own private house for a FC if we can have instanced houses, because this would give me a chance to upgrade it without having to buy a medium house or a mansion (if they would make such a system) and I know that finally a FC can have their own house thanks to that.
Last but not least I want to say something about the gardens and the chocobo stable. I do think that they would have a problem with instanced houses that have a gardens patch and and stable because both have a timer on them. But this would be no problem if they just create stables in the cities that anyone can use. You can go there, give them your chocobo and the items that are needed to train him and than you can take him away again when you want it. When you get there to take it back you than have to pay a specific amount of gil which depends on the time that it was there. With that it would be still cheaper to have a chocobo stable at you FC house but at the same time you can always train him even if you don`t have a FC with their own house and we don't need it in our private houses. The same can be said about gardening. We do have a gardening guild in Gridania and they could implement a NPC which you give the seeds, the necessary soil and pay them gil depending on the worth of the seeds and after a time you can get back to the NPC and get your goods. I am not sure if this can be done with all seeds or if they can use cross breeding but at least you can get some goods from it and you still have the chance for the other ones with your FC gardens. With this FC still matters but at the same time people can still train their chocobos and have some vegetables on their own. And it would be easier for SE with instanced houses because they now will only exist when we will go there and the stables in the cities and the NPC for gardening are much less than if everyone has its own ones in the instanced houses. I mean they already do something like that with the raising of a racer chocobo. We give them the license and after a time we go back to get our chocobo.
I don`t have knowledge about the technological side of it but since some other MMOs can do that why should SE not be able to do the same especially after it was possible in some way in the much older FF11.
Sorry for this long post but I wanted to post this idea for a long long time and hopefully someone may get some ideas from it. I hope you liked it. And sorry for my language its not my mother tongue.