Dropbox wins on UX, which is where FOSS fails almost every time. A quick way to know whether such projects will fail: if they mention anything about the technologies used. Making it obvious to use and "just work" is what is needed.
I think it's pretty obvious that this isn't intended, at least in it's current incarnation, to be a dropbox-killer. It doesn't need to pander to the same audience.
"dares to mention technologies used" is only a killer for a subset of all possible audiences. For example, knowing that Git is hacked together with C and bash doesn't make it any less useful to me (ie, someone who isn't afraid of computers)
The problem is setting up the Git server. Even if you use Github - and then you have to pay if you don't want your files open to the public - creating the repo, adding the keys, understanding what they have to put in the Address field, etc is still extremely difficult with the knowledge (and patience) of the average person.
Too bad that is actually the hard part.