How much POB are we talking about? First of all why would we entertain the idea of permanently removing BTC from the ecosystem? Today's change can be next decade's car (or for you bears that want to start a fight for no reason, it could also be next decade's trash).
Also I still don't understand how POB is necessary. I read it but ELI5 someone? Because I don't see why its necessary.
POB address will be pegged to a reputation address. At some point, you don't want to screw your reputation address and start another one because your reputation also cost you money. It's not a fool proof system but it gives more incentives to play by the rules. Serious businesses also have an opportunity to build trust quicker.