remoteStorage is an elegant solution in a lot of ways, but there are some problems:
* Apps written in this style have a very hard time being real-time collaborative. Maybe this will be solved by WebRTC, but it's a lot easier with a server component. (Sandstorm has several real-time collaborative apps, like EtherPad, EtherCalc, and Wave. Currently you can share these apps with other users by copy/pasting the URL; the sharing model will get more sophisticated eventually).
* You need to set up a storage server for the apps to use, or use one of the big providers that like to do data mining. You then need to connect the app to the correct server, which is extra busy-work.
* The permission model of these storage servers isn't terribly sophisticated. Often you'll end up granting the app broader permissions that you really want.
* There is, of course, nothing stopping the app from storing data to other places as well, nor is there any isolation between separate documents opened by the same app. (On Sandstorm, each document is a separate instance of the app in a separate sandbox which cannot communicate with the outside world without permission.)
Edit: Missed that you said you're working on RemoteStorage. Probably would have phrased differently if I noticed. Wasn't meant to be an attack. Sorry! (We actually like remoteStorage apps a lot in that they are often easily ported to Sandstorm. :) )
Actually you got it right the first time: Working with* not on. =)
My wording could probably have been a bit more precise.
Having worked with it for the past few months, I do agree with a lot of your sentiments on the shortcomings of the server-less application model, but in many applications where user privacy is a high priority (which is increasingly the case since the Snowden revelations), having a fully portable, standards-based storage solution that you can host on your own if you choose is incredibly compelling.
With the remoteStorage-based serverless app I'm working on right now, it's been quite a challenge trying to reach feature parity with existing client-server apps on the market today. But once we even get close to achieving feature parity, I believe we'll have a very compelling solution.
* Apps written in this style have a very hard time being real-time collaborative. Maybe this will be solved by WebRTC, but it's a lot easier with a server component. (Sandstorm has several real-time collaborative apps, like EtherPad, EtherCalc, and Wave. Currently you can share these apps with other users by copy/pasting the URL; the sharing model will get more sophisticated eventually).
* You need to set up a storage server for the apps to use, or use one of the big providers that like to do data mining. You then need to connect the app to the correct server, which is extra busy-work.
* The permission model of these storage servers isn't terribly sophisticated. Often you'll end up granting the app broader permissions that you really want.
* There is, of course, nothing stopping the app from storing data to other places as well, nor is there any isolation between separate documents opened by the same app. (On Sandstorm, each document is a separate instance of the app in a separate sandbox which cannot communicate with the outside world without permission.)
Edit: Missed that you said you're working on RemoteStorage. Probably would have phrased differently if I noticed. Wasn't meant to be an attack. Sorry! (We actually like remoteStorage apps a lot in that they are often easily ported to Sandstorm. :) )