True, there is player housing and now fleet (guild) housing.
What they don't have, is customizable housing. And that is a potential money earner. I remebered second life, it was not even a game. You could buy plots and buy stuff for on it, and it had a really good crafting tool with which you could even make your own objects. People spent a lot of money just for a virtual home.
But STO is not set up that way. So it would be a huge investment to create such a thing. For instance, the Foundry tool is very poor, and so difficult and user unfriendly to use that not a lot of people would actually customize. They would have to build a completely new creation tool, or buy an expensive licence for one, and customize that, first.
Next they would have to overhaul the whole structure, because the instances are based on a limited amount of pre-existing maps, not on numerous custom maps of different sizes. And there is not a system for numerous adresses, like in SWG, so that would need to be set up too or else each space would be very isolated (you would get no people there).
Its just a very risky investment, a lot of expense, and are enough people going to use it?
But there could be cheaper ways. The Starbase structure works. So make personal spaces like it, with fixed positions for furniture that you can buy/earn to upgrade. And to give it a personal touch, for instance, the choice of a limited number of different maps. Attach these with a link to the ship interior or starbase interior, and voila. They could do this if it turns out the Starbases are profitable. Lets say, semi-custimizable personal housing, where you will have to work with invites.
Personally i LOVED the housing system in SWG, its one of the things i missed the most.
Of course whilst i'd love to rent a place on Vulcan or even own a moon of my own where i can plonk a house, your starships interior would be good, although people couldnt just stroll in and have a look (i'll admit any time i'd go into a shop in SWG i'd explore the rest of the house)....I loved my shop!
Take note, if they made something like this and sold decoration packs on the C-Store i'd spend a bloody fortune!...it's probably a good thing for my marriage they dont.