Due to the focus on privacy,
I think Diaspora makes perfect sense as intranet social network for Companies, Govt, Colleges etc. I would wish Diaspora pivots in this direction
Diaspora as it has been, is centralized, and doesn't seem to be anything but a smaller, crappier Facebook.
Friendica does what Diaspora was supposed to do, and well, and can integrate with the Facebook API and download your personal Facebook feed into your Friendica feed.
But if you were after a social network that is completely decentralised i.e. no servers, take a look at Nightweb. http://nightweb.net/
Diaspora is as much decentralized, as many pods participate in it. There are many single user pods which demonstrates its decentralization pretty well. So your statement above is false. I'd compare it to federated XMPP network - there are major servers with many users, and there are single user servers as well.