Diaspora wanted to make an app so that servers can communicate between each others. There are already tons of chat protocols, creating another one would be stupid. diaspora would not host anything, while facebook make both the app and the hosting, and keeps the data.
Facebook also failed to implement some sort of craigslist, which is something that would really serve a big purpose for people in general (advertise for any sort of stuff, jobs, dating, help needed, local announcements...). I don't understand why they don't do that.
> I have never thought the Diaspora project would succeed, because it's the social network nobody wants.
Diaspora was not created to be wanted, diaspora was created so that users can care a little more about their data. Facebook makes people share data that the marketers try to get. People don't really care about those issues, and investors would not fund something like diaspora. So don't talk about investors and users like they're the same people. Currently there are no technology to make people keep the control over their data and use them with something like facebook. If the tech was there and it was as appealing as facebook, it would be used.