I kind of feel like you contradict yourself. I agree, it's not doable for "normal people" to set up their own social network services. Not only is it not doable, most people actively do not want to do it, even if they had the knowledge. For this reason, the phrase "rented infrastructure" is like nails on a chalkboard to me. Nobody will rent infrastructure to save their privacy. The only way you'll get people to pay for it is if it has
functional superiority over facebook, meaning killer features. They will still want someone else to host it, support it and patch it. That becomes expensive, fast. Expensive for "normal people" who are in "normal groups" like parent/school groups, their kids' football teams etc -- organizations who do not have budget for "information technology privacy initiatives", because nobody understands what it is, nobody cares and nobody sees what the return on investment is (maybe because there is none, which techies will never admit).
I think the unfortunate truth is that people in general don't care about their data. There are people who do, but they normally have very special reasons to and they will never be a majority, unless we have massive social upheaval worldwide. Hopefully that will not happen, but if it does the technology is already there to solve that problem when it comes along.
There are many free and admirable initiatives such as "riseup" who provide communication services free of charge to organizations working for social change. There are frameworks for you if you care about your data and want to disconnect: but most people don't care. And if you care, you will move away from normal people. That's the unfortunate truth, and it's not changing anytime soon. I'm all for educating the masses, but people will not switch facebook for encrypted e-mail. Not because a lack of encryption workshops, but because it's not the same thing, and facebook is as far as functionality goes, objectively better at solving the problem people perceive.