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What's wrong with a space station or a Fleet Carrier?
The fact that they're still in space.
Or, let's as this: Why do Navy personnel go on Shore Leave?
Why do so many episodes of popular/famous sci-fi shows spend so much of their time on the surfaces of planets (Star Trek/Star Wars), or in search of a particular planet (Battlestar Galactica/Lost in Space)? Because we are, ultimately, terrestrial beings. We need gravity, it's health for us. Space is not, space hates us and wants us dead.
As a species, we want to populate and multiply, and a ship or station has only a finite amount of space for that sort of thing.
Space stations require a tremendous amount of administration and are generally immobile. We'd miss out on too much game play to play Space Station Administrator, and that's just not in keeping with what Elite is at its core. Not that I don't think it would be a fun distraction, but it wouldn't stay a distraction, it would become too much of a focal point, much in the same way too many people have forgotten there's an entire game here and are hyper-focused on BGS as if it were a game in and of itself. But at the very least, it does force them to engage in aspects of game play. What would a station administrator do?
Yes, it takes some time and the slightest bit of effort to set down on a planet. It also would likely take a lot of currency - and there have been plenty of callings for credit sinks for quite some time now. Establishing a planetary installation would also mean upkeeping it, which would once more force us back into our ships, to collect materials, resources and supplies necessary to maintain it. It would also mean accumulating credits, which would once more mean hitting the ship, getting out there to do things.
Yes, I realize many of these things could be accomplished via a Fleet Carrier, really all of them COULD, but I suspect they won't. I suspect Carrier functions will still be rather limited in scope, as compared to the features and functions stations and planetary installations offer - and that can easily be expanded to a personal, surface base as well.