Re: Any kind of central "real world identity" system is RIPE for abuse. Period.
DNS is a hierarchical decentralized system. The worst of both worlds.
Federated social networks are yet another compromise between central and decentralized. It's not a new idea, it's been tried and failed before (eg. XMPP). What's the incentive for big ISPs to maintain a complex decentralized infrastructure when their users are happy enough with their simple central silos? There is none.