I know not all user would have need of this, but let me explain my situation.
I'm a student game developer and I can't always get access to a gaming rig whilst at uni (they are almost always booked out for lessons). So I figured that would be no issue as I could develop from my SkyComputer, Via my 2009 MacBook Pro. Except if I did that and ran out of sky credits I would be unable to access my work. However If there were to be an FTP system that would allow me to browse the files on my SkyComputer, zip the project I've been working on and download it, that would be mean I can work on it when I get home to my gaming rig, or just carry on with a script I was writing, then take it home to test.
I know I could upload my latest build to my google drive account before I log off, but the fact of the matter is that my daily free access time with the new LiquidSky would be better spent developing and testing whilst I have the resources to do so.
I'm also aware my situation is somewhat unique, but I can't help but feel that others may be in a similar situation where having the ability to extract files from the SkyComputer after they log out would benefit them greatly.