If the list is going to be itemized, that's a privacy concern.
If you default on a loan, do you really have a right to hide your identity from the people who loaned you that money? Surely a promise of anonymity would be conditional on keeping the promise to pay. Even if not explicitly stated as such, if you promise to pay me $50/week and I promise to give you my car after 20 weeks, I sure as heck don't have to give you the car if you don't pay. And if they are kept anonymous, how can the people eating the default know that the default actually occurred?
If it isn't, then haven't we been shown those numbers already?
Not quite. Patrick has posted and then unposted numbers. He hasn't, at least as far as I am aware, made a list of actual defaulted loans, even without their identity.
I'm not sure the lack of such information impacts Patrick's peccability at all.
It's the difference between "Sorry, you lost 100 Bitcoins" and "Sorry, you lost 100 Bitcoins because I loaned 100 Bitcoins to Jeff in early December, transaction ID Y, and he made interest payments until last week, and has since been unable to pay principal." The former asks for a level of trust that would be unnecessary if he were telling the truth. It's roughly the difference between just telling someone else their property was stolen versus giving them a copy of the police report.