I don’t think the problem is only younger users and their lack of money. It’s not like the vast majority of older users of the internet want to deal with anything more complicated than putting a username and password into one site and being done, even if they do have the money to spend on a domain.
Personally I love the idea of POSSE. I think it would genuinely be an improvement on the way things are on the internet right now. But the barriers to entry, both in terms of finances and knowledge, are just too high for the vast majority.