If we just make a better algorithm, people won't find our UI design intolerable.
If we just offer them some privacy, they will pay real money for it.
Long before there was a web, people were giving up privacy and freedom for the convenience of credit cards.
If the decentralized web is going to fly, it needs to START with the social sciences.
We can all nerd out over algorithms that make it happen, or use math to prove that it can't be done, only once the economists have created a model in which it might, theoretically be done. And the social scientists have created a model in which a critical mass of people will make the necessary choices, when presented with them.
As it stands, most people are not willing to pay: http://www.telegraph.co.uk/technology/news/11047801/Would-yo...
I would be willing to pay that _and more_ in a heartbeat if given the option. But, in social science terms - I understand the problems with centralization much better than most, I'm willing to put up with much worse UI than most, and I'm wealthier than average.
Heck I'd probably pay just because I think the underlying technology is neat! But that makes me a pretty extreme outlier on the broad spectrum of humanity that are choosing, en-masse to use Facebook, which means that I either need to use Facebook, or nothing.