Realistically, it seems likely that there just wasn't enough demand among existing Tesla owners for that use case. If/When Tesla gets more market share, that could very well change. My understanding is that they are still engineering all their chassis to support the fast swap technology, so they haven't entirely trashed the idea.
http://www.csmonitor.com/Business/In-Gear/2015/0312/Tesla-ba...
http://www.latimes.com/business/autos/la-fi-hy-tesla-battery...
There may be good reasons that swappable batteries don't make sense, but interest data gathered from this station doesn't contribute.
> They must make an appointment in advance to get their pack swapped, and they will pay a fee said to be roughly equivalent to the cost of a full tank of gasoline--perhaps $50?
> And the swapping process isn't fully automated, unlike the one supposedly presented by Musk 21 months ago.
> The company never released details on how that system worked, or answered questions on how the battery's liquid-cooling system could be disconnected and reconnected, and any lost coolant replaced, within a 90-second swap.
> But the slow pace of the single swap station differs markedly from the fast-growing Supercharger network, where any Tesla owner can drive up, charge for 20 to 40 minutes, and drive away with a battery recharged to about 80 percent of capacity.
So maybe you save 20 minutes on net, but it costs $50 and you have to sign up a week in advance. Why would anyone use it?
Tesla hasn't released anything on their own, but the battery swap patent is now public: https://electrek.co/2016/10/25/teslas-battery-swapping-magic...
They essentially designed and built an industrial robot, R&D costs for which easily range into 8 digits.
This looks like a failed good faith effort to me. They thought they had something (as did much of the rest of the car industry), turned out they were wrong and they're cutting their losses.
The point is that that particular swap station was not in good faith, and therefore it's (predictable) non-use gives you no additional data about the public's demand for swapping. (You may, of course, infer something from the fact that Tesla doesn't think it's viable.)
It has to do with the way the incentive structure is set up: there is tax credit of order $1,000 per vehicle if the vehicle has battery swap capabilities, which necessitates "available" infrastructure. If Tesla invested huge in battery swap tech and then decided it wasn't going to work, they still have massive incentives to open up a single, highly inconvenient swap station in order to recoup part of their investment through the tax incentive.
Once marketshare increases, car sharing increases, etc., and people become more accustomed to sharing property (and charging becomes the norm for everyone), the convenience of a 3 minute battery swap will likely win over - and Tesla will be ready to roll out their tech.